Forum Title: Hot water coming out of cold taps
Please excuse the length of this. My experience reading all kinds of help forums tells me to give all the details I know. About 6 months ago a problem started. In the bathroom sinks, all of them, upon turning on the cold knob, hot water will come out for about 10 seconds before turning cold. All the sinks have one spigot and two knobs (one hot one cold). If you shut the tap off for 10-15 min and then do it again, the problem will recur. Also, in the toilet, where I installed a bidet attachment, coming off the line, hot water will come out (ouch!). Investigating, I have individually, one sink at a time, shut off the water lines, then after flushing the hot out of the cold lines from the other sinks I'd wait, then try for the problem again. It would recur. Thus ruling out any mixing or hot water going up, and crossing over at that particular sink (whose lines I'd shut off). Other problems I have ruled out (I think): The expansion tank has a good pressure and the bladder is intact; I don't think it's heat coming up via convection from the hot water heater and heating the cold lines; I don't think (although, this one I'm not sure), I don't think it's pressure in the hot water tank pushing hot water backwards into the tank's supply line back to some split (it sometimes feels a little warm, but not hot like the hot pipes do. And the problem is not in the kitchen cold). I don't know if there is a back-flow preventer on the hot water tank supply line (I'm not sure what it looks like. And I'm not sure that they use them on residential anyway. Youtube only takes my knowledge so far, ya know?) I think the problem must then be at the tub. Which brings me to some NEW information. Same problem? Separate problem? 5 or 10 minutes after my wife showers, if I go in there I turn on the spigot all the way hot and wait for it to get warm before pulling the plunger knob on the spigot to make the shower go on. The problem is, lately it can take 90 seconds for it to be anything other than ice cold, and this is with the knob turned all the way to hot. Oh, in the tub, there is ONE knob that you rotate on and full rotation is hotter direction, less rotating is cold (do I make sense?). This morning I had a revelation. After standing there, still waiting for it to go hot, I pulled the 'turn-the-shower-on-plunger' and it quickly went warm. I shut off the water completely, dropping the plunger, turned the water back on all the way hot, but kept it coming out of the tub spigot, and yes COLD!! There must be mixing there right? And my wife says the minute or more of cold in the tub happens a lot. And it is harder to find a good temp. in the shower. Big breath. Now, the problem MAY have begun (I'm not sure) around the time I replaced the spigot at that tub. But all I did was unscrew the spigot from the pipe and screw on a new one. I did use pipe thread tape. But I did feel like I had to give it a good half turn (or more) extra, kinda tight, to get the spigot to face downward. HELP HELP HELP --Brett
Post By: APRIL OLIVER (Rockville, MD), 10/30/2016
I don't know. But we've been in this house for 8 years and this is a new problem.
Are the pipes in the attic or is there some kind of heating element to keep pipes from freezing in the attic
What type of water heater Is there a recirculating line on the hot water system Or the shower valves in the house a thermostatic style not to be confused with pressure balanced