Welcome to Plbg.com
Thank you to all the plumbing professionals who offer their advice and expertise

Over 675,000 strictly plumbing related posts

Welcome to Plbg.com and PlumbingForum.com. The best online (strictly) PLUMBING advice, help, dyi, and informational plumbing forum. Questions and discussions about toilets, sinks, faucets, drainage, venting, water heating, showers, pumps, water quality, and other exclusively PLUMBING related issues. Please refrain from asking where to purchase a product, or business, pricing, or legal questions, or for contractor referrals, or any questions not related to plumbing. Keep all posts positive and absolutely no advertising. Our site is completely free, without ads or pop-ups. We do not sell your information. We are made possible by:  

Post New
Search
Log In
How to Show Images
Newest Subjects
 Hot water coming from cold water bathroom sink fixture
Author: candyman (TX)

Some specifics at the front end:

Mfg: Barand, circa 2001 (for bathroom lavatory and tub shower fixtures)
Mfg: Taco, circa 2016 (whole house recirculating hot water pump)
Water source: filtered rainwater for entire house
Recent plumbing repairs: Replaced both heating elements and both thermostats in 85gal Marathon (circa 2001) HWH

Problem: After this week's HWH repairs (which required draining/refilling the HWH), water from the upstairs bathroom sink cold water faucet now comes out very hot for a while before finally getting lukewarm, then "cold". If I turn the tub/shower thermostat to 90degrees or lower this seems to help with water temperature at the sink.

ETA, also seems to be a problem with downstairs bathroom faucet.

ALSO....the cold water line entering the HWH (at top of tank) is hot.....

Questions: Could this be an age/sediment clog/coincidence situation with the shower valve? Is this considered a 'crossover' problem'? Could this be a recirc pump check valve malfunction or the HWH thermostats that were recently installed? Why does the water temperature problem happen at the sink? Since remedy may require cutting into the wall, should the entire shower/tub fixture be replaced, seeing as how Barand no longer exists? Thanks for any help!



Edited 1 times.

Post Reply

 Re: Hot water coming from cold water bathroom sink fixture
Author: packy (MA)

it is probably in the whole house recirculating hot water check valve.
it may be a separate check valve or it my be integral to the pump.

Post Reply

 Re: Hot water coming from cold water bathroom sink fixture
Author: candyman (TX)

Thanks, we've unplugged (wall plug) the Taco recirculating pump and so far the problems listed have resolved, although it takes several minutes and some gallons of water for hot water to get to the fixtures upstairs. Plumbers working on coming out to assess. I am hoping it is not the thermostat mechanism in the shower set.

Post Reply

 Re: Hot water coming from cold water bathroom sink fixture
Author: candyman (TX)

Plumbers (all 3 of them) just left after some head-scratching and diagnostics. Best guess is a defective thermostatic mixing valve (?terminology) in the tub/shower set. We and plumbers are scouring the internet to find a possible replacement. Might require changing the entire valve unit for this shower.

Our Taco recirculating HW pump is also suspect, since it becomes very, very hot when plugged in. Taco has been unplugged for several days and everything is working like normal with that unit out of the equation. But right now we're only trying to change out the shower cartridge (unless we can't locate a replacement).The proverbial Pandora's box.

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:
PlumbingSupply.com


Copyright© 2021 Plbg.com. All Rights Reserved.