Over 698,000 strictly plumbing related posts
Plumbing education, information, advice, help and suggestions are provided by some of the most experienced plumbers who wish to "give back" to society. Since 1996 we have been the best online (strictly) PLUMBING advice site. If you have questions about plumbing, toilets, sinks, faucets, drains, sewers, water filters, venting, water heating, showers, pumps, and other strictly PLUMBING related issues then you've come to the right place. Please refrain from asking or discussing legal questions, or pricing, or where to purchase products, or any business issues, or for contractor referrals, or any other questions or issues not specifically related to plumbing. Keep all posts positive and absolutely no advertising. Our site is completely free, without ads or pop-ups and we don't tract you. We absolutely do not sell your personal information. We are made possible by:
Author:
twogooses (NY)
I am having issues with my Water Heater. It's a slantfin tankless boiler (TR-30 PT). It's running on a 4 zone setup. I typically only use one of the zones though. We've been in the home for a year and a half. Towards the end of this winter I started finding a few gallons of water draining from the T&P valve every few days.
I tested the expansion tank and found it to be leaking water from gauge, leading me to believe the diaphram has ruptured and we needed a new one. I bought the same model replacement. An Amtrol #60 and gauges to test our home water pressure and PSI on tank. I attached the water meter to our outside hose line and read about 56 PSI. I then took the precharged (to 12 PSI) new tank and charged it further up to about 55 PSI before installing it. I then removed the old expansion tank to find it almost completely filled with water. Replaced it with the new tank. Turned water line back on and power to water heater. Gave it a day or so.
Now I'm still seeing water, perhaps more. So, even though the exp tank was shot, what else could be causing this? Autofill valve? I don't think the T&P valve is bad as it is draining water once the meter reaches the max level on the valve which is 30 PSI. The slantfin temp range was set at 160 - 180. I lowered this to 140-160 and still same issue.
I then turned on the water from my faucet for a while, and the pressure on slantfin was hovering between 2 and 10. Got the temp on slantfin below 140, down to 120ish. It didn't seem to instantly turn back on, but then turned on the first floor of our home (ZONE 1 of 4), slantfin initiated and watched the gauge on the unit. As it heated the water from 120 to 140 (where min is set) it gradually increased pressure until right about hitting 140 the pressure then hit 30 PSI and T&P valve started draining.
Should I not have charged the new tank? I was under the understanding this needed to be same if not a few PSI below water pressure. Does this change if on a multi-zone house. If using a tankless system?
Should my T&P valve be rated to take on more pressure than 30 PSI?
Should the precharge be the same as the water supply line even if the tank will be placed after a "water pressure regulator valve" set between 12-25 PSI?
Any information would be greatly appreciated. I'm stumped...
|
Post Reply
|
Author:
North Carolina Plumber (NC)
With that much air pressure in the tank its just like not having a tank at all. There is no place for the expanding water to go except for the pressure relief valve. Set the air pressure in the tank to its original charge.
|
Post Reply
|
Author:
twogooses (NY)
Many thanks! So factory setting was 12 PSI, should i return it to that or somewhere near that then? And correct me if I'm wrong, but I should be able to just turn off the system relieve it of pressure, than drain the expansion tank back down? No need to remove to do that right?
Much appreciated!
|
Post Reply
|
Author:
North Carolina Plumber (NC)
Yes, you are correct.
|
Post Reply
|
Author:
hj (AZ)
Is this an expansion tank for the hot water heater or the boiler, because if it is for the boiler, then the pressure should be set at about 15 psi.
|
Post Reply
|
Author:
twogooses (NY)
It's for a Slant Fin TR-30 PT Boiler with tankless water heater. I adjusted it to 15ish PSI (hard to tell exactly with my gauge) and it seems to have fixed the problem so far!
Thanks everyone!
Edited 2 times.
|
Post Reply
|
Please note:
- Inappropriate messages or blatant advertising will be deleted. We cannot be held responsible for bad or inadequate advice.
- Plbg.com has no control over external content that may be linked to from messages posted here. Please follow external links with caution.
- Plbg.com is strictly for the exchange of plumbing related advice and NOT to ask about pricing/costs, nor where to find a product (try Google), nor how to operate or promote a business, nor for ethics (law) and the like questions.
- Plbg.com is also not a place to ask radiant heating (try HeatingHelp.com), electrical or even general construction type questions. We are exclusively for plumbing questions.
Search for plumbing parts on our sponsor's site:
Special thanks to our sponsor:
|