Poor Hot Water at Kitchen Sink

[Eric74]

We just recently bought an older, 1978, 2 bed 2 bath town home in good condition generally. It's furred masonry, sheetrock interior walls.

The 40gal. electric water heater is centrally located with short runs to both baths, and perhaps only 20' to the kitchen. Both bath fixtures enjoy hot water quickly, but the kitchen sink hot water takes far too much time to arrive, and the strangest symptom is that after filling the sink with hot water, we can go back 5 minutes later and the water from the hot side is cold again. Unless we run the water back to hot again, taking some time, the water remains at best tepid through washing the dishes.

I'm a retired building inspector and the house I built had none of these issues. I put new sink supplies, faucet and quarter turn shut offs at the kitchen before we moved in. I don't know what the supply piping material is, but the h/c stubs are copper of course.

Anyone have an idea what's going on here, and maybe what I could do to remedy this issue?

Thanks!

 

[havasu]

What part of the world are you in? How cold is it? Are your pipes insulated? Do you have a water saving device on your faucet? What size pipe do you have rnning to the kitchen?

 

[Eric74]

Thanks havasu, I need to fill out on profile. I'm in Southern Arizona. I'd have to open a wall to check for pipe insulation, but it's typically not done here. Again guessing that the supply piping would be 3/4", with 1/2" stubs at the fixtures. No water saving devices.

I should mention that water pressure at all fixtures is good, with no difference between hot or cold pressures.

And the hot water seems to remain hot at the bath fixtures with no 'going to cold' quickly as does the kitchen sink faucet.

I can't see any evidence of polybutylene piping, for example, all observable piping including main service is copper, but it was used heavily during those years.

 

[voletl]

Did you check and make sure both elements are working

 

[Eric74]

No, but I presume they are because the hot water elsewhere has good temperature, the kitchen has good hot water also, simply that going back just a few minutes later it's cold, and takes forever to warm up again. Far longer than other homes I've owned and experienced.

 

[CT-18]

I am just taking a shot in the dark here. Try turning off the cold under the sink.

 

[Eric74]

I am just taking a shot in the dark here. Try turning off the cold under the sink.

Great idea and thanks! There was some success in that although the sink faucet gave cold water within ten minutes after filling the sink, it did seem to begin to warm up a bit quicker while finishing the dishes.

I'm starting to conclude that the 'run' from the water heater is below ground then pops up in the kitchen plumbing wall, an outside wall. That being, there's little chance of solving this issue.

Thanks much for the suggestion!

 

[CT-18]

I was thinking that one of your fixtures is letting the cold mix with the hot. That's why I said to shut off the cold. I am not much of a residential service guy, more big construction. Good luck

 

[Eric74]

I was thinking that one of your fixtures is letting the cold mix with the hot. That's why I said to shut off the cold. I am not much of a residential service guy, more big construction. Good luck

Your post had a great idea I thought, since the other fixtures don't have this issue it seemed at least logical.
I did put a new sink faucet on, but the simple mixing valve is just piping, though of course one could be blocked by some factory crud or solder over splash.
Maybe I'll pick one up at a second hand store to try an alternative.

Thanks again!