ELM Aquastar 125vp ng tankless

[Ladiesman217]

My ELM Aquastar 125vp ng tankless water heater is still working after 20 years of operation. Recently it became a bit noisy when water flow was fast.

I performed my very first heat exchanger flush this week. One hour of vinegar flush with pump, 2 hour wait with pump off, then one hour of final flush with pump. Then rinsed with clean water. The vinegar was still pretty clear after the flush.

After the flush I installed a new cold water input filter in the heater, and cleaned and lubricated the water valve. The water valve lubrication stopped the water heater noise.

The original thermostat has been bad for about 6 years (would not automatically regulate the gas - fixed position not variable). The old thermostat probe was perfectly clean when it was removed. No mineral deposits on it after 20 years.

I installed the new OE replacement thermostat that I recently picked up (two units, one spare), and calibrated per the service bulletin.

The unit now runs like new with regulated water temperature.

I also picked up some other hard to get water heater parts just in case I need them in the future!

I wonder how long this unit is going to last?

 

[Ladiesman217]

Today I rebuilt the water valve in the 125-vp for the first time. You are supposed to check it every 5 years.

Upon inspection, the rubber diaphragm was hard as well as deformed.

Installed a new diaphragm and lubricated gas valve pushrod per the service bulletin.

Everything was pretty clean after about 20 years of use.

 

[Sponsor]

 

[Jadnashua]

The minerals dissolve in the acid, so it could appear to be still clear after flushing. Now, as it loosens stuff up, you might get some chunks, but run the stuff around long enough, and they'd dissolve too. If you have soft water, it might not need a cleaning annually, but even then, eventually, you're likely to get some buildup which will diminish its ability to transfer the heat and your max temp and volume can go down.

 

[Ladiesman217]

I suspect that I am being supplied with low mineral content in the municipal (state) water system. In addition, my water heater does not run at a high water temperature.

The water heater operation and water flow rate did not change after the flush.

I can see why people have different luck and different maintenance requirements with water heaters of all kinds in different parts of the country.

http://www.softwaterfiltration.com/hard-water-areas/

http://homewater101.com/articles/hard-water-across-us

That being said, I should do a flush more often than once in 20 years. Next time that I do a flush, I think I will remove and inspect the PRV for mineralization before and after the flush.

 

[Fixer69]

My AquaStar VP 125 has been faithfully serving me for 30 years. Parts availability is a problem. The thermocouple went bad and I couldn’t find one anywhere.
I went to the local Home Depot and bought a universal thermocouple. I cut off the end of the new thermocouple that is heated by the pilot. Then I cut off the piece of the old thermocouple that was in the pilot flame and soldered the new one to the wire coming from the gas valve. I then used mechanics wire to hold the tip of the new sensor in the flame. And VIOLA! Works perfectly!
I AM concerned about availability of gas valve parts though. I rebuilt my gas valve about 3 years ago. Parts are rapidly becoming NLA.

 

[Mark169]

Today I rebuilt the water valve in the 125-vp for the first time. You are supposed to check it every 5 years.

Upon inspection, the rubber diaphragm was hard as well as deformed.

Installed a new diaphragm and lubricated gas valve pushrod per the service bulletin.

Everything was pretty clean after about 20 years of use.


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Where do you get parts for an ELM Aquastar 125 VP