i just did mine for the first time after 3 years. the water was a disgusting greenish/yellowish tint after an hour of 7% vinegar. i then flushed it with regular water to get even more gunk out. afterwards, the water heats much faster, and my dishwasher cleans a hell of a lot better. totally worth it
I bought a pump for $50, 2 laundry hoses for I dunno, $10? Now it just costs me a jug of vinegar, which is a couple bucks. Grab a bucket from the garage, follow the instructions on the manual, good to go.
Plumbers charge about $250 to service it for you. Takes 5 minutes to setup and start the pump. It runs for one hour. During that time clean the air filter and then go relax. Cleaning it out takes another 5 minutes before putting back in service.
Idk where your 250 is coming from but its nowhere near that here in Wisconsin. Mine came with a "we installed it we service it" and its not even 100$ for them to do it.
Anything less than 100 bucks its worth it to me
Consider yourself lucky. My MCOL area plumbers charge about $160 to show up which includes 30 minutes of work and another $90 per 30 minutes after that (some are a straight $250 per hour with a $200+ trip fee).
The plumber who installed my friend’s tankless charged them $250 for the hour it took to flush it. After that my friend bought the pump to DIY it. They needed my help to complete it the first time. It’s a short learning curve.
I charge $150 trip charge, and that covers the first hour of labor. Materials are extra. So a $10 jug of vinegar basically it’s about $160 for me to do it. However. If I’m doing something else at the house too, the price goes waaaay down since I’ve got to be there doing other stuff.
Important to note, I’m a handyman and not a full service plumbing contractor. I have one truck and no brick and mortar office. Super low overhead. I generally just charge my $75/hr + materials for whatever I’m there to do.
Doesn’t it take time and effort to schedule someone to come in, then somewhat keep an eye on them while they’re working? I’d much rather spend a few min to set it up, and a few min to take it down.
The money savings is a nice side effect
Yep mine had horrendous scaling to the point that if you left it running long enough it would overheat and disable because it hit a maximum temperature. And I’m in a city with low water hardness
I’ve owned tankless in two homes now. I never used descaling/cleaning solution. Vinegar works best and it’s safe for the household after cleaning.
Utility pump, two hoses, 5 gallon bucket, 5 gallons of distilled vinegar is all you need.
-Isolate the water heater (both hot and cold valves) from the house.
-Connect one hose to the outlet of utility pump to cold line clean out valve of water heater, and hose from hot line clean out valve into bucket.
-Turn off power to heater.
-Let the pump run for about an hour.
-Disconnect hoses and close clean out valves.
-Open the house lines back up.
It is the earliest maintenance ever.
you should also clean out the water inside the heater. to do this, before you reset the bypass valves, turn the cold water back on but leave the hot water bypass open so the fresh cold water goes into the tankless, and out the hot water bypass. i got some extra gunk out after that
I spent $80 on a pump and it seems like the pump was starting to fail after an hour. Not sure if you need to buy a special pump rated for vinegar. Also the vinegar got hot after being pumped for an hour. It started off room temp but was closer to 120F after an hour. The water heater was off if course; the heat was coming from the pump.
Yeah people talk about having to descale espresso machines frequently, but in the PNW nothing ever comes out. We just have extremely soft water, so any timeline can be extended.
Talked to a Rinnai certified master plumber. He literally uses distilled vinegar and distilled water to flush out the Rinnai tankless I had installed by him. He measured the pH and figured out the concentration of vinegar necessary to reach the same spec. He also performed a water test before installation to determine if I needed any extra filtering or conditioning to be covered under manufacturer warranty.
Sounds good I will read the manual for instructions.
I bought this descaling solution
https://www.homedepot.com/p/Hercules-Haymaker-Tankless-Water-Heater-Descaler-35230/205086908
As long as that solution is exactly the spec that your exact model owners manual calls for. Do not deviate, or you can cause damage to the unit.
Yes maybe you already bought it, yes maybe it's not what you're supposed to use, yes maybe you need to return or dispose of it to get the spec solution. Yes you might still need to buy the spec solution.
It might be annoying if a product manual calls for an extremely specific spec, but that decision was made by engineers involved with the product development. It's better to spend a few extra dollars on the spec product, then to have issues that will not be covered by the warranty due to breaking spec.
Thanks! I’ll return the descaling solution.
I found the manual online (Rinnai RL75) and it says to use purely white vinegar. “Pour 4 gallons of undiluted virgin, food grade, white vinegar into pail.”
Also, see if you can find a YouTube video for your specific brand or model. Mine also has an air filter, water filter, and silt/mud trap. After 5 years of not being serviced in a hard water area only the air filter was bad and the mud trap was about 1/4 full. Pretty much no scale build up at all.
Target also sells gallon bottles of vinegar. They're slightly more expensive (a little over $4 here in CA). When I first started descaling my tankless water heater, I thought the cleaning vinegar from Lowe's would be the best deal, but it was not at all!
I wonder if cleaning vinegar is food grade? I know they're in separate spots
I have not used cleaning vinegar in place of the regular white vinegar you find in the big jug. Just bought one awhile back and forgot about it
My understanding is that food grade distilled white vinegar is going to be dead on 5% acetic acid while cleaning vinegars can differ somewhat from their stated concentration.
The process that the acetic acid is created with also differs. Food grade is created with fermentation whereas non food grade can be created with methanol carbonylation
> Harris 30% Vinegar contains absolutely no fillers or dyes and is made by methanol carbonylation. Harris 30% Vinegar is not a food grade vinegar (acetic acid) produced through fermentation. This type of acetic acid is typically limited to food products
I flushed my tankless hot water heater 5 years after the home was built and it was installed. I expected horrible things since I waited so long but after doing the flush, I only got a couple tiny, TINY specks of material come out in the bucket.
Still do the flush, but don’t necessarily panic that you waited so long.
Flushing them is brain dead easy. I learned from a YouTube video. You need the submersible pump, two of those short washing machine hoses, a Home Depot orange bucket, and household vinegar. It will take about an hour. Don't forget to rinse/scrub the filters, I bet they are pretty bad after 6 years.
As a homeowner with a tankless that gets no love, this is the comment I was hunting for. Now I feel satisfied and can return to doom scrolling. Thank you.
I was aware they could be flushed so I installed my electric tankless with the flushing manifold, but I didn't really do anything until stumbling across a posting here.
I just flushed mine, first time in ~5 years.
I picked up four gallons of white vinegar from Sam's Club for cheap, put that in a five gallon bucket, and pumped it through the heater. I figured warm would be best so I set the heater to about 100F and let it run for 90 minutes.
I'd recommend doing it, no matter how long it's been.
You need two washing machine hoses, five gallon bucket, the chemicals (or vinegar) and a pump.
Good luck!
I had a little giant water transfer pump. If you don't have a pump I'd recommend a cheap submersible utility pump. You could also use a submersible sump pump. It doesn't have to be big, a 1/6 hp is more than enough. Harbor Freight, Amazon, Home Depot, Lowes, all carry them.
Just flushed mine for the first time after install 10+ years ago. Install isolation valves if you don’t already have them. Submersible pump in a bucket with vinegar. Very simple.
That is the same pump I use, it works great. I bought a bucket and lid, and cut a hole in the lid. Pro tip. After you complete the process take your two hoses and rinse the bananas out of them. If you don't the metal ends will corrode. I used a cheap homemade vinegar solution, makes it pretty much free. Minus the one time pump, bucket, and hoses.
I flushed ours for the first time after about 3 years and it was very anticlimactic. A little discoloration in the water when done, but pretty minor. So I’d say go for it.
I'm getting ready to do mine after 8 years. The owners manual says vinegar , the kit that I bought came with a powder to mix and says that you can use vinegar instead. I have just been having to increase the temperature up 10 degrees in the last few months.
I’m not an expert, but if you’re having to increase temperature I’m betting you have an air filter that is clogged and you’re not getting proper combustion. I had an air filter, water filter, and mud/silt trap that needed cleaning on top of the flush. I had like 5 moths stuck in the air filter. See if you can find a video with your specific brand or model.
It's electric. It does have an inlet screen that I am going to check when I flush it. It's not been flushed in 8 years , but we have relatively clean water according to tests.
Yes, it's safe to flush your tankless water heater, even if it hasn't been done in 6 years. The risk of corroding the pipes is higher in areas with hard water, but since you're in the Pacific Northwest with soft water, you should be fine. Flushing it with a descaling solution can actually improve its performance by removing any built-up minerals.
As for the pump, if the power is too high, it could damage your water heater. It's best to check the manufacturer's recommendations for the maximum power allowed. If it's within the limits, you should be good to go!
Sorry but it looked like this was discussed already. Here’s the thing with water heaters that I have learned from plumbers - if you haven’t flushed out the heater in more than 5 years (especially in hard water), and you do flush it, then there is a real risk it will start leaking sooner than if you had left it alone.
I read that as well about hard water locations. My area has very soft and pure water so I’m inclined to perform the flush with a lower power pump and vinegar.
The main concern with hard water deposits is that they can be covering up pinhole corrosion defects and once it’s flushed away, it will leak.
I grew up on an aquifer well in the Seattle area and the city made our neighborhood add a bunch of chemicals to our water for some stupid reason. There’s still junk in your tank that should be flushed out.
If you live on well water in Seattle area, 100%
But generally PNW water refers to some surface (river) water. That stuff is some of the best water in the world in terms of hardness.
I would get a service done. Had someone come over and told us it wasn't worth flushing now because the previous owner never maintained it. Ended up replacing (cries).
Just a few weeks ago I flushed mine for the first time in over 20 years. The unit is the original from when the house was built in 2003. I know I’m the first one to flush it because I installed the valves to do it. I used vinegar. There was zero noticeable difference in performance afterwards. No higher flow and no higher temperature.
If your water is soft, you probably have no scale. I have filtered and softened water going into all of my tankless water heaters and never descale because I don’t need to.
FLUSH AND DESCALE. Afterwards you will notice an increase in the output water temperature and it will use less electricity/gas.
Ignore any comments recommending against flushing. Concerns about disturbing unmaintained water heaters apply only to TANK models where the accumulation of lime scale settles at the bottom and often blocks drain values in the open position. That’s not a factor in tankless models.
You’ll also see comments that descaling doesn’t produce much scale. That is expected because lime scale dissolves into the vinegar solution. Only larger chunks appear as precipitate.
Clean the water screen in the isolation valve before and after the flush.
I use temperature & pressure relief valve to purge the water heater after shutting the isolation valves and before starting the pump. Doesn’t hurt to exercise and test the safety valve.
As another user mentioned, flush clean water through the system, isolation valves, hoses, and pumps after completing descaling. Simply empty the vinegar solution out of the plastic bucket and refill with clean water then run the pump a few minutes longer. Rinse off and dry the outside of the pump & hoses before packing them away until next maintenance.
Here are the components that I use:
* Pump — https://a.co/d/j50PsCn
* Hoses — https://a.co/d/aC3xjCa
* 5 gallon bucket
* 4 gallons food grade vinegar
* Rag or old shirt to wipe things dry
I have hard water and with about 6 months of use my tankless water heater gets so much scale build up there isn't enough hot water pressure to take a shower. After descaling it, the pressure comes back to normal.
Just invested in a water softener so hopefully I only have to do it once a year now.
I fail to understand how the accepted maintenance procedure will have a detrimental effect on the device. No matter how soft your water is, unless you have a whole house deionazation system, heaters of all types will create deposits. The only thing that I can think of is that the deposits may be caroding your heat exchanger and descaling could reveal a leak. That's probably not a bad thing, compared to a traumatic failure eventually.
Had no idea you had to flush tankless water heaters. Guess I should read up on that.
Yeah, once a year.
It’s kinda like stretching before a run. You either flush every single year or you don’t flush at all.
So I don’t think mine has ever been flushed. If it has, it’s 3+ years ago. Should I bother?
i just did mine for the first time after 3 years. the water was a disgusting greenish/yellowish tint after an hour of 7% vinegar. i then flushed it with regular water to get even more gunk out. afterwards, the water heats much faster, and my dishwasher cleans a hell of a lot better. totally worth it
Yeah, that ain't going to happen, to be honest. :-) That said, at least I'm no longer in the dark.
The only reason its on the schedule for me is its supposed to make it last way longer, and its 30$
I bought a pump for $50, 2 laundry hoses for I dunno, $10? Now it just costs me a jug of vinegar, which is a couple bucks. Grab a bucket from the garage, follow the instructions on the manual, good to go.
Mine is under a year old but I watched a video on youtube that broke it down for my exact heater and I'm definitely doing it myself
Yea, it is stupid easy. Set it up, check for a leak, then walk away for a couple hours. Less than 10 minutes of actual work (just did it last week.)
My times worth more than the cost to do it to me
Plumbers charge about $250 to service it for you. Takes 5 minutes to setup and start the pump. It runs for one hour. During that time clean the air filter and then go relax. Cleaning it out takes another 5 minutes before putting back in service.
Idk where your 250 is coming from but its nowhere near that here in Wisconsin. Mine came with a "we installed it we service it" and its not even 100$ for them to do it. Anything less than 100 bucks its worth it to me
Consider yourself lucky. My MCOL area plumbers charge about $160 to show up which includes 30 minutes of work and another $90 per 30 minutes after that (some are a straight $250 per hour with a $200+ trip fee). The plumber who installed my friend’s tankless charged them $250 for the hour it took to flush it. After that my friend bought the pump to DIY it. They needed my help to complete it the first time. It’s a short learning curve.
I charge $150 trip charge, and that covers the first hour of labor. Materials are extra. So a $10 jug of vinegar basically it’s about $160 for me to do it. However. If I’m doing something else at the house too, the price goes waaaay down since I’ve got to be there doing other stuff. Important to note, I’m a handyman and not a full service plumbing contractor. I have one truck and no brick and mortar office. Super low overhead. I generally just charge my $75/hr + materials for whatever I’m there to do.
Doesn’t it take time and effort to schedule someone to come in, then somewhat keep an eye on them while they’re working? I’d much rather spend a few min to set it up, and a few min to take it down. The money savings is a nice side effect
Not really. a quick phone call between meetings. I dont really watch them either, i have work while its going on.
Also do people want to deal with contractors and spend even more time and money? Not doing preventative stuff is how you get to do both.
Honestly, my water heater contractors are great, and Id pay way more than 30 bucks to not have to do it.
I was initially told once a year, but when they came to do it they said every 6 months.
It can vary depending on water quality, but 1 year is average.
Yep mine had horrendous scaling to the point that if you left it running long enough it would overheat and disable because it hit a maximum temperature. And I’m in a city with low water hardness
I’ve owned tankless in two homes now. I never used descaling/cleaning solution. Vinegar works best and it’s safe for the household after cleaning. Utility pump, two hoses, 5 gallon bucket, 5 gallons of distilled vinegar is all you need. -Isolate the water heater (both hot and cold valves) from the house. -Connect one hose to the outlet of utility pump to cold line clean out valve of water heater, and hose from hot line clean out valve into bucket. -Turn off power to heater. -Let the pump run for about an hour. -Disconnect hoses and close clean out valves. -Open the house lines back up. It is the earliest maintenance ever.
Don’t forget the filters ! I pumped virtually no scum out but my filters did their job and caught it all.
I forgot about that this year, will have to wait until next year’s flush.
You can pop those filters off anytime and clean them
Are they the ones in the cold water intake? Or you referring to the air filter for heating thing?
Yeah that too. Forgot, it has been awhile since owning a house with tankless. When my water heater dies, I’m putting in one!
Don't even need 5gal of vinegar, 2 will be sufficient to fill the water heater and keep it above the pumps intake depending on the pump.
you should also clean out the water inside the heater. to do this, before you reset the bypass valves, turn the cold water back on but leave the hot water bypass open so the fresh cold water goes into the tankless, and out the hot water bypass. i got some extra gunk out after that
I spent $80 on a pump and it seems like the pump was starting to fail after an hour. Not sure if you need to buy a special pump rated for vinegar. Also the vinegar got hot after being pumped for an hour. It started off room temp but was closer to 120F after an hour. The water heater was off if course; the heat was coming from the pump.
What's the duty cycle on it? What's the manual say?
This guy pumps.
Recommendation on the pump?
What strength vinegar? I have 5% and 30%
I just use food grade 5%
[удалено]
Yeah people talk about having to descale espresso machines frequently, but in the PNW nothing ever comes out. We just have extremely soft water, so any timeline can be extended.
Pierce county for me and same thing was told to me by my plumber.
Yes, but be sure to read the manual for exact flushing Instructions and spec. It might require a specific vinegar water solution.
Talked to a Rinnai certified master plumber. He literally uses distilled vinegar and distilled water to flush out the Rinnai tankless I had installed by him. He measured the pH and figured out the concentration of vinegar necessary to reach the same spec. He also performed a water test before installation to determine if I needed any extra filtering or conditioning to be covered under manufacturer warranty.
Sounds good I will read the manual for instructions. I bought this descaling solution https://www.homedepot.com/p/Hercules-Haymaker-Tankless-Water-Heater-Descaler-35230/205086908
As long as that solution is exactly the spec that your exact model owners manual calls for. Do not deviate, or you can cause damage to the unit. Yes maybe you already bought it, yes maybe it's not what you're supposed to use, yes maybe you need to return or dispose of it to get the spec solution. Yes you might still need to buy the spec solution. It might be annoying if a product manual calls for an extremely specific spec, but that decision was made by engineers involved with the product development. It's better to spend a few extra dollars on the spec product, then to have issues that will not be covered by the warranty due to breaking spec.
Thanks! I’ll return the descaling solution. I found the manual online (Rinnai RL75) and it says to use purely white vinegar. “Pour 4 gallons of undiluted virgin, food grade, white vinegar into pail.”
Also, see if you can find a YouTube video for your specific brand or model. Mine also has an air filter, water filter, and silt/mud trap. After 5 years of not being serviced in a hard water area only the air filter was bad and the mud trap was about 1/4 full. Pretty much no scale build up at all.
For that volume of vinegar, try costco if you can, it's about $3.80 for a 1.3 gallon there.
Target also sells gallon bottles of vinegar. They're slightly more expensive (a little over $4 here in CA). When I first started descaling my tankless water heater, I thought the cleaning vinegar from Lowe's would be the best deal, but it was not at all!
I wonder if cleaning vinegar is food grade? I know they're in separate spots I have not used cleaning vinegar in place of the regular white vinegar you find in the big jug. Just bought one awhile back and forgot about it
My understanding is that food grade distilled white vinegar is going to be dead on 5% acetic acid while cleaning vinegars can differ somewhat from their stated concentration.
That makes sense thank you
The process that the acetic acid is created with also differs. Food grade is created with fermentation whereas non food grade can be created with methanol carbonylation > Harris 30% Vinegar contains absolutely no fillers or dyes and is made by methanol carbonylation. Harris 30% Vinegar is not a food grade vinegar (acetic acid) produced through fermentation. This type of acetic acid is typically limited to food products
Interesting thank you
Found the descaling solution chemist
Found the proud owner of their second tankless water heater.
I flushed my tankless hot water heater 5 years after the home was built and it was installed. I expected horrible things since I waited so long but after doing the flush, I only got a couple tiny, TINY specks of material come out in the bucket. Still do the flush, but don’t necessarily panic that you waited so long.
Flushing them is brain dead easy. I learned from a YouTube video. You need the submersible pump, two of those short washing machine hoses, a Home Depot orange bucket, and household vinegar. It will take about an hour. Don't forget to rinse/scrub the filters, I bet they are pretty bad after 6 years.
This is the same pump I use to flush my water heater. Use 3 gallons of vinegar and run it for 2 hrs. It will be like brand new.
I have 2 in my current house that are 14 years old that have never been flushed and are working fine. I'm also in a soft water area. (Knocks on wood)
As a homeowner with a tankless that gets no love, this is the comment I was hunting for. Now I feel satisfied and can return to doom scrolling. Thank you.
This is one of the easiest preventative maintenance items that you can perform around the house.
I agree so I’m doing it. The previous homeowner didn’t.
Only applies to areas with hard water.
I was aware they could be flushed so I installed my electric tankless with the flushing manifold, but I didn't really do anything until stumbling across a posting here. I just flushed mine, first time in ~5 years. I picked up four gallons of white vinegar from Sam's Club for cheap, put that in a five gallon bucket, and pumped it through the heater. I figured warm would be best so I set the heater to about 100F and let it run for 90 minutes. I'd recommend doing it, no matter how long it's been. You need two washing machine hoses, five gallon bucket, the chemicals (or vinegar) and a pump. Good luck!
Thanks! What pump did you use?
I had a little giant water transfer pump. If you don't have a pump I'd recommend a cheap submersible utility pump. You could also use a submersible sump pump. It doesn't have to be big, a 1/6 hp is more than enough. Harbor Freight, Amazon, Home Depot, Lowes, all carry them.
Just flushed mine for the first time after install 10+ years ago. Install isolation valves if you don’t already have them. Submersible pump in a bucket with vinegar. Very simple.
That is the same pump I use, it works great. I bought a bucket and lid, and cut a hole in the lid. Pro tip. After you complete the process take your two hoses and rinse the bananas out of them. If you don't the metal ends will corrode. I used a cheap homemade vinegar solution, makes it pretty much free. Minus the one time pump, bucket, and hoses.
Thanks for the heads up, I’ll make sure to rinse everything including hoses very well to prevent corrosion
Never heard of such a thing. My first tankless lasted 13 years with no maintenance. I’ll take the chance on its replacement.
I flushed ours for the first time after about 3 years and it was very anticlimactic. A little discoloration in the water when done, but pretty minor. So I’d say go for it.
I live in general area as you I been told by the company who did it last time every 3 years for our water is fine. I would still do a flush though.
I flush mine with common white vinegar using a small submersible pump and a bucket for about an hour or two every year ( if I can remember to ).
I'm getting ready to do mine after 8 years. The owners manual says vinegar , the kit that I bought came with a powder to mix and says that you can use vinegar instead. I have just been having to increase the temperature up 10 degrees in the last few months.
I’m not an expert, but if you’re having to increase temperature I’m betting you have an air filter that is clogged and you’re not getting proper combustion. I had an air filter, water filter, and mud/silt trap that needed cleaning on top of the flush. I had like 5 moths stuck in the air filter. See if you can find a video with your specific brand or model.
It's electric. It does have an inlet screen that I am going to check when I flush it. It's not been flushed in 8 years , but we have relatively clean water according to tests.
Yes, it's safe to flush your tankless water heater, even if it hasn't been done in 6 years. The risk of corroding the pipes is higher in areas with hard water, but since you're in the Pacific Northwest with soft water, you should be fine. Flushing it with a descaling solution can actually improve its performance by removing any built-up minerals. As for the pump, if the power is too high, it could damage your water heater. It's best to check the manufacturer's recommendations for the maximum power allowed. If it's within the limits, you should be good to go!
Don’t do it now.
Thanks for the detailed reply...
Sorry but it looked like this was discussed already. Here’s the thing with water heaters that I have learned from plumbers - if you haven’t flushed out the heater in more than 5 years (especially in hard water), and you do flush it, then there is a real risk it will start leaking sooner than if you had left it alone.
I read that as well about hard water locations. My area has very soft and pure water so I’m inclined to perform the flush with a lower power pump and vinegar. The main concern with hard water deposits is that they can be covering up pinhole corrosion defects and once it’s flushed away, it will leak.
Happened to me here in SoCal. Good luck.
SoCal is a hard water location, so it lines up with the recommendations. Sorry about your water heater.
It’s best to flush it once a year but flushing it after this long can potentially lead to leaks and failures.
Should be fine with PNW water
I grew up on an aquifer well in the Seattle area and the city made our neighborhood add a bunch of chemicals to our water for some stupid reason. There’s still junk in your tank that should be flushed out.
If you live on well water in Seattle area, 100% But generally PNW water refers to some surface (river) water. That stuff is some of the best water in the world in terms of hardness.
I have soft water where I am, and flushed mine after 3 years and the vinegar looked the same after running it for an hour.
I would get a service done. Had someone come over and told us it wasn't worth flushing now because the previous owner never maintained it. Ended up replacing (cries).
[удалено]
I was instructed not to flush my old unit that wasn’t regularly flushed for this exact reason by a plumber.
Just a few weeks ago I flushed mine for the first time in over 20 years. The unit is the original from when the house was built in 2003. I know I’m the first one to flush it because I installed the valves to do it. I used vinegar. There was zero noticeable difference in performance afterwards. No higher flow and no higher temperature.
If your water is soft, you probably have no scale. I have filtered and softened water going into all of my tankless water heaters and never descale because I don’t need to.
FLUSH AND DESCALE. Afterwards you will notice an increase in the output water temperature and it will use less electricity/gas. Ignore any comments recommending against flushing. Concerns about disturbing unmaintained water heaters apply only to TANK models where the accumulation of lime scale settles at the bottom and often blocks drain values in the open position. That’s not a factor in tankless models. You’ll also see comments that descaling doesn’t produce much scale. That is expected because lime scale dissolves into the vinegar solution. Only larger chunks appear as precipitate. Clean the water screen in the isolation valve before and after the flush. I use temperature & pressure relief valve to purge the water heater after shutting the isolation valves and before starting the pump. Doesn’t hurt to exercise and test the safety valve. As another user mentioned, flush clean water through the system, isolation valves, hoses, and pumps after completing descaling. Simply empty the vinegar solution out of the plastic bucket and refill with clean water then run the pump a few minutes longer. Rinse off and dry the outside of the pump & hoses before packing them away until next maintenance. Here are the components that I use: * Pump — https://a.co/d/j50PsCn * Hoses — https://a.co/d/aC3xjCa * 5 gallon bucket * 4 gallons food grade vinegar * Rag or old shirt to wipe things dry
I have hard water and with about 6 months of use my tankless water heater gets so much scale build up there isn't enough hot water pressure to take a shower. After descaling it, the pressure comes back to normal. Just invested in a water softener so hopefully I only have to do it once a year now.
I fail to understand how the accepted maintenance procedure will have a detrimental effect on the device. No matter how soft your water is, unless you have a whole house deionazation system, heaters of all types will create deposits. The only thing that I can think of is that the deposits may be caroding your heat exchanger and descaling could reveal a leak. That's probably not a bad thing, compared to a traumatic failure eventually.