[Julie Jones]

I live in a small condominium in North Miami, Florida. We have two buildings, each is serviced by it's own boiler. For the last three years I have been complaining about a lack of hot water. They have called in a plumber, but he has not been able to fix the problem.

I have intermittent hot water at all faucets. When I fill the bath tub in particular, I cannot introduce any cold water or it becomes all cold water. When I use only hot water, it will heat up then go cold. If I shut down the hot water and restart it again the whole process begins again... the water heats up then goes cold.

I have the same problem at the Kitchen Sink. HELP!

[massplumber2008]

Hi Julie

It sounds like you have a CROSS CONNECTION somewhere in the system. Here, almost any single lever faucet or single lever tub/shower valve could have a bad balancing spool or mixing cartridge. The issue could even be a bad washing machine valve, or any place, like say, an outside faucet that might have hot and cold water connected...that kinda odd stuff.

The point here is that you need to find the cross connection by a "process of elimination". The simplest place to start is to go to every sink that has a single lever faucet and then shut off the cold water supply under each sink. Now, test the TUB, and see if the issue has resolved itself. If the issue is resolved, you'll then open one shut off valve at a time and retest at the tub until you find the faucet that is causing the issue. The defective faucet will obviously need to be repaired or replaced.

If no faucets show the cross connection then pop back and we'll tell you the next steps to take to isolate the washing machine or other things you can think of, OK? Tub and/or tub & shower valves cannot usually be isolated, so as a last resort it may be necessary to change out the parts to these, but only as a last resort.

Mark