Installing external expansion tank on a tankless water heater

Plumbing Forums

Help Support Plumbing Forums:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

kyoboof

Member
Joined
Oct 21, 2018
Messages
11
Reaction score
0
Location
saskatchewan
Good evening. I posted previously about my coaire tankless water heater issues and these forums were a great help. I had a pressure reducing valve start leaking/losing pressure.

With the help of these great forums we replaced the PRV and added an inline pressure gauge to help monitor the pressure.

2 months later (now) the new PSI gauge sprung a big leak. I replaced the gauge again and all is well.

This got me thinking. Why did a PSI gauge completely fail 2 months in? Could my expansion tank be bad? the psi guage never reads above 19 psi. Other than the gauge leaking the unit functions properly.

I shut off the water going to the unit and drained the unit by manually lifting the pressure release valve until the unit had zero pressure at the gauges, I took my pressure gauge and measured the PSI at the expansion tank shrader valve and it measured ZERO. Does this mean my internal expansion tank failed? Did I test it properly?

If the answer is yes, and the tank has failed. I would like to know if its possible and how to plumb in a external expansion tank. ( if it is possible it will be done by a journeymen gasfitter/plumber) dont worry! Please note this tankless unit also heats my house.

Attached are some detailed pictures of the unit. The expansion tank is circled in red and I also attached a picture of the gauge that was leaking. hopefully this is enough info.

Thanks so much.
 

Attachments

  • 3.jpg
    3.jpg
    109.6 KB · Views: 30
  • 49305816_2264915600443825_378178845439688704_n.jpg
    49305816_2264915600443825_378178845439688704_n.jpg
    118.8 KB · Views: 22
  • 49781202_409269083148453_3680142152051982336_n.jpg
    49781202_409269083148453_3680142152051982336_n.jpg
    94.3 KB · Views: 26
  • 49896773_281832362684952_3198931426342862848_n.jpg
    49896773_281832362684952_3198931426342862848_n.jpg
    85.1 KB · Views: 23
  • 49898973_321799605096065_5043613072451698688_n.jpg
    49898973_321799605096065_5043613072451698688_n.jpg
    467.7 KB · Views: 23

Latest posts

Back
Top