# Tankless water heater and Moen positemp pressure-balanced shower valve



## VictorPlumber (Feb 26, 2019)

Hello all:

Client called me: 
Tankless water heater, Moen positemp pressure-balanced tub/shower valve. When water goes thru bottom spout – temperature is hot enough, when diverter switched to go to top shower head – water coming from shower head is luke warm. 

Everywhere else temperature is ok. One shower/tub in a house. 

I think hot water pressure is less than cold and cold water overpowers hot water in pressurised shower riser. 

What if I take out pressure-balancing spool from 1222 cartridge – would it work without spool? Is it possible to do?
Client doesn’t have small children so scalding is ok. 

How would you fix it so it would be possible to take hot shower ?

Would appreciate any ideas. 
Thanks.


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## Fatpat (Nov 1, 2015)

VictorPlumber said:


> Hello all:
> 
> Client called me:
> Tankless water heater, Moen positemp pressure-balanced tub/shower valve. When water goes thru bottom spout – temperature is hot enough, when diverter switched to go to top shower head – water coming from shower head is luke warm.
> ...



I would remove the shower head and see if there is still a temperature issue. If so replace then shower head with a higher flow model or remove the flow restrictor. 

If the issue continues(with the shower head removed) then I would replace the balancing spool/cartridge.


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## Logtec (Jun 3, 2018)

Replace the cartridge/spool.
While you have the C/S out, flush out the lines.


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