Too hot water downstairs, cold upstairs

[Donald G Hammonds]

We have a fairly new furnace installed onto a really old system of steam heat/ cast iron radiators. THe hot water for the house comes from the furnace and its INCREDIBLY hot at the first floor and at the second floor bathroom sink, but the tub has barely warm water (it’s right next to the bathroom sink) Any ideas on the problem and what we can do to fix it?

[AKPlumberParticipant]

Perhaps someone else here may have a better response for you, sorry that I can’t be alot of help on this one without looking at it. But I wanted to ask whether your tub valve is a pressure balanced valve or not. This could be the issue where it is set to decrease the amount of hot water it allows through (to avoid scalding). It would help if you stated what brand/model shower valve you have so that one would know if this particualr valve can be adjusted to allow for more hot water volume.

[philosParticipant]

oh boy! will ask hubby tomorrow but its a really old claw foot and I don’t think there’s any pressure valves or things like that. Brand – not a clue, but will see if anything printed on it – any thoughts on where I’m supposed to look?

[AKPlumberParticipant]

By “claw foot” I assume you mean the old fashioned 2 handle brass body types which commonly connected to risers via compression fittings, like the old Gerber and Kohler types. If this is the case it’s a non-pressure balanced valve, and no adjustments can be made to it regarding pressure of flow from hot and cold. The reason these types of valves are no longer code in new construction and remodels is due to the risk of scalding basically. Anyway, your situation is a tough one to diagnose without testing and eyeballing, but I could postulate several possibilities….one, that during the installation of the new furnace to the potable hot water system some crud or solder or whatever dislodged and found it’s way into your shower valve manifold and is possibly restricting the hot side valve stem…..perhaps the stem just went bad. Can you see the supply lines in between the sink and tub? Are they connected to one another or are the fixtures being supplied separately? Quite a few variables. Is the hot side water on the tub valve always just warm or only when other fixtures are turned on? I’d suggest starting with the tub valve and changing out the hot side valve stem after flushing the manifold just for giggles and see what happens. Hopefully someone else has a better idea?

[philosParticipant]

sounds reasonable. will pass on the info and see what happens this weekend. Thanks for the help

[Author]

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