danielhudson

Hey there.
So we have an old home (1902) that is 3 stories.
We currently have a tenant in our ground floor apartment. She just informed me that she is unable to get the hot water to come out of the bathroom sink tap.
She could let it run and run and it will not get hot at the sink tap.
Her kitchen sink tap works fine.
Our kitchen sink tap works fine.
Our 3rd floor bathroom sink gets hot pretty quickly but
our 2nd floor bathroom sink tap has the same problem that out tenant does...
Our 2nd floor bathroom sink hot water has NEVER gotten hot (unless I take a shower in there beforehand) and we've just learned to live with it, since our primary bathroom is on the 3rd floor...
Anyway, this is a new problem ( we think) for our ground floor bathroom sink as our previous two tenants never mentioned it.

We have a tank (blech) water heater 80 gal on the ground level of the house, so her bathroom is actually the closest to the source of hot water.

We can't figure this out.

Any ideas oh plumbing gifted folks out there? Thanks!

Redwood

I would say you have a hot/cold cross connection either at or near the affected sink. Usually this would involve a faucet that can be turned on both hot and cold yet have the actual discharge out the spout turned off.

Moen and Mixet single handle valves can also do this when they need to be repaired.

Nestor_Kelebay

Another thing to check is any shower heads where you can turn off the water flow at the shower head itself.

If you have one of those shower heads, then the flow can go through the shower valve from the cold water supply piping into the hot water supply piping. The result is that you can get cold water coming out when you open either the hot or cold water faucets somewhere else, like the bathroom sink.

If it were simply a blockage in the hot water piping, then you'd have a weak flow of hot water out the affected hot water faucets. If the pressure with which the cold water comes out is as strong out the hot water faucets as it is out the cold water faucets, then I'd agree there's a cross connection somewhere.