Bosch Aquastar 125VP on demand gas hot water heater and I think I need a new thermocouple

[Russell B. Marz]

I had this unit installed back in 1995 and aside from a few quirks, it has worked very well. About 1 year ago the pilot light would not stay on and I had a friend play with it and he got it working again up until a few weeks ago. I have had a couple of plumber/heating specialists take a look at it but they are unfamiliar with the unit and they want 3,000 to $5,000 to install a new unit. It is my understanding that the thermocouple, once it heats up enough, will send a signal down to a gas valve telling it to stay open. Thus my quest for a new thermocouple of which, when I called Bosch up, they said that they no longer have them and they have been out for about 1 year. I don't know enough about thermocouples other than it was suggested that I might be able to put in a universal couple. I went down to our local plumbing store and Home Depot and they were not very helpful. Perhaps there is a used unit or maybe someone has some suggestions. It just seems crazy to replace the entire unit when it work perfectly fine except for this $20.o0 thermocouple. Is there anyone out there with an Aquastar 125VP with the same problem? HELP!

 

[DonL]

10 Years old ?

Get a new one.

And tell your friend not to play with it.

 

[Sponsor]

 

[Terry]

Here is one that was installed in 87
https://terrylove.com/forums/index.php?threads/bosch-aquastar-tankless-review.50271/

20887 Thermocouple for 125VP and 80VP

You may need to bit the bullet on that. Twenty years was a pretty good run though.

 

[Master Plumber Mark]

I agree with Terry... This is a big problem with tankless water heaters ..... once they reach a certain age
their is a good chance that they have discontinued all the parts for them....or the company has gone under or been sold off..
Lots of companies have re-designed their units and I have heard from out Rheem dealers they are only required to stock parts back for 7 years on power vented units...

you got 20 years out of tankless heater which I think is RARE...
Dont expect the same luck with a new one


for 3000--5000 you can install a lot of tank type water heaters if you have the room
but whatever floats your boat