Flushing Tankless Water Heater

It all depends on how hard your water is as to how long you can go between flushing

How old is the heater?

I do it yearly like clock work. Sub pump, vinegar or sometimes descale solution, flush it, good to go. It's super easy. Tankess flush video

quote:

---

This is something I need to start doing. Do you have a link to the kit you purchased? Are they specific to the tank manufacturer or are they universal?

---

They are universal. I did it for the first time 3 days ago. My water heater was installed a year ago. It was a relatively easy process. Flushed it with cleaning vinegar for an hour. The difference in the color of the vinegar was profound and I have soft water.

Make sure you have the service valves and taps, you should, but I would make sure.

My plumber recommended every 2-3 years on parish water, would go at least annually on well water. I've done it once, there was some visable scale, but nothing crazy, so going to stick with every other year.

Hardest part was walking down the attic stairs with a couple gallons of vinegar in a bucket

I do it every 2 years, super easy. Bought a pump from harbor freight and washing machine hoses.

I think you have to do the descaling process per the recommended time interval, or it may affect your warranty.

I have two Rinnai and flush both of mine yearly, and currently use a product called Calcifree by Rectorseal - it is < $20 and only has to be circulated for 20 min, so saves time. My plumber recommended it to me. I get it at the plumbing supply, but it is available on Amazon. Prior to that I have gone with a white vinegar then graduated to Hercules Haymaker. Any of those are fine, I prefer the Calcifree because it takes less time and only 2 gallons of water in the bucket. One tip - buy a grit guard to go in the bottom of your bucket so your pump doesn't pick up the scale particles that sink to the bottom of the bucket and recirculate them.

I pull the in-line filter (turn supply valves off first) about every 3 mos, if it has scale in between flushings, I'll scrub it in some vinegar for a few minutes to get it clean.

Flushing a tankless water heater is one of the easiest maintenance tasks I do around the house and it saves a boat load over having a pro do it and will add life to your tankless.

Mine must be living on borrowed time. It was installed in 2008 and this thread marks the 1st time I'm even aware they may need flushing. I have a neighbor who works in one of those small portable grey buildings the Post Office uses in rural areas. They have small tankless water heaters in them and her building is 30+ years in service and it hasn't had a flush and still works well.

I think I'm going to leave my tankless water heater alone!