Shower not hot after having water tank installed

Over 704,000 strictly plumbing related posts

Welcome to Plbg.com (aka: PlumbingForum.com) where plumbing advice, education, information, help and plumbing related suggestions are provided by some of the most experienced plumbers and plumbing contractors anywhere who all wish to "give back" to society. Since 1996 we have been free without popup or other invasive ads and known to be 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 find and/or 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 track you. We absolutely do not sell your personal information. We are made possible by:

Post New

How to Show Images

Newest Subjects

Shower not hot after having water tank installed

Author: ssarnold (MD)

I had a new gas tankless water tank installed a few days ago but it is not completely hooked up yet. Still using old electric water heater. Now all faucets and shower in other bathroom have hot water, except my main shower which is lukewarm only when turned to hottest temp. It worked perfectly before the water was turned off when installing new water heater. The shower that doesn't have hot water is only about 6 months old. I checked the valve which is a Moen posi-temp valve. It was already set to highest setting. I checked the cartridge and that was super clean as well.
What else could be the problem?

Post Reply

Re: Shower not hot after having water tank installed
Author: packy (MA) did you turn the water on briefly with the internal parts removed?
Post Reply

Re: Shower not hot after having water tank installed
Author: ssarnold (MD) No Wouldn't that shoot water everywhere if I did that? What is the purpose of doing that?
Post Reply

Re: Shower not hot after having water tank installed
Author: packy (MA) hang a big towel to keep the water spray confined. there may be debris at the inlet/s of the valve and the cartridge prevents it from being flushed out of the valve body
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:

Plbg Advisor List Find A Plumber Plumbing Manufacturers Directory theplumber.com

Special thanks to our sponsor:

to FAQ's - to popular subjects - to plumbing books - to Tankless 101 - to plumbing history - to helping charities - to contact us