Hot water problem

[SkunkedAgain]

I'm never home anymore (work travel) but every month or two my wife will call to tell me that she can't get any hot water to take a bath, it's just warm. We used to have a 1966 water heater that failed one year ago. This happened with the old heater too. I'm assuming that this isn't a water heater issue. We get good pressure in general and all of the other faucets in the house can always get hot water. I've never had a problem taking showers either....this is an every once in a while problem and only associated with the tub.

Background: it's a 1950's rambler in the twin cities and the plumbing runs aren't very far.

What could be the problem?

[Redlantern]

Sounds like the tub valve is the issue. Have you ever worked on it? Old ones can be a pain to disassemble and find parts for. Sometimes it's easier and less expensive to just replace the old one with something newer.

[Powerstroke]

I agree, sounds like you've got a bad mixing valve on the tub. I assume that this is hot/cold combined with a single handle. If its two separate knobs for hot and cold then there may be another issue.

[SkunkedAgain]

It actually is two separate handles

[shizzy]

just to verify, when this happens in the tub if you were to use another faucet in the house at the same time you would have proper temp hot water?

[SkunkedAgain]

Correct

[CAMAN]

Is this the original faucet to the house or was it replaced within the last 30 years or so? Sounds like an anti scald device not functioning properly, but if the faucet is the same age as the house then they didn't have anti scalds that long ago. I would probably replace the entire faucet or atleast the internals if you can still find parts.

[SkunkedAgain]

Great questions. It's entirely possible that they are original, but if I had to guess they look like a 1960s/70s faucet combo. I'll start pulling things apart next weekend (the fish will have my attention this weekend). Thanks for the advice.