Shower Goes From Hot to Cold But No In Between
LESLIE: Pat in Delaware, you’ve got The Money Pit. How can we help you today?
PAT: Oh, thank you for taking my call.
TOM: Our pleasure.
PAT: I have a plumbing question.
PAT: I moved into a new home that’s 10 years old and the hot water in the tub, which is a combo shower/tub, goes directly from hot/cold to boiling; there’s no intermediate. And when I’ve had a plumber out there, they checked it to get into the cut-out to see what the shutoff valves were. There was no cut-out.
Now, I have another one, which is a stand-up shower. It does the same and there’s no way to get into the plumbing either. So the …
LESLIE: So there’s no access panel on those back walls?
PAT: Right, exactly. And the plumber said there wasn’t anything he could do.
TOM: Obviously, the valves are behind the wall. But let’s talk about the kinds of valves.
So your concern is that you get sort of a shower shock where it goes from cold to hot?
PAT: Well, yeah. And I don’t want anybody getting a burn, you know?
TOM: Does it happen like when you’re in the shower and somebody else is running something somewhere in the house?
PAT: No, no. It just – that’s the way it is all the time. It goes …
LESLIE: Pat, have you checked the actual water heater? On the tank, there’s a temperature-demand gauge that you could be like, “I want it to be on A, B or C.” And it’s the thermostat, which tells you how hot you want it to be. And you might just have it all the way cranked up.
PAT: No. My husband went down and looked at it and he said – I want to say 120, 140, something like that?
TOM: Yeah, that’s way too hot. You want it to be more like around 110. But I think that you have another problem here and that is that if the valve is just going from cold to hot, there’s sort of no middle ground, then you just might have a bad valve. And if there’s no access …
PAT: Is that the same thing as a diverter? Because the plumber said something about he would check – the diverter sometimes wear out.
TOM: Well, the diverter is going to divert water from the faucets to the shower.
PAT: Oh, OK.
TOM: OK? From the tub faucet to the shower.
LESLIE: It could be the mix valve, though, right?
TOM: It depends on the kind of valves; sometimes it’s all in one. But I think it’s a problem with the valve; you may need to replace the valve.
There is a type of valve called a pressure-balance valve. The nice thing about a pressure-balance valve is that once you set the mix of hot and cold, it doesn’t matter what happens elsewhere in the house, the mix always stays the same. So you can’t get a situation where somebody flushes the toilet or runs a dishwasher or something like that and all of a sudden, the temperature changes.
TOM: So you don’t get the cold shock or the hot shock. But I think the bottom line is that you’re going to need a new valve. And to get – to replace that valve, you would open the wall behind the bath. So if that – if there is a wall behind the bath that’s covered with drywall, it’s very easy to sort of surgically cut out a piece of drywall and access the back.
PAT: Well, the only problem is the back of the shower, where the faucets are in the shower, is the living room wall. That’s where it is.
TOM: OK. But I mean how old is your house? So it …
PAT: Ten years old.
TOM: Alright. So it’s drywall. Drywall is repairable. I understand it’s your living room wall and it’s not going to be pretty to have a hole in your living room wall.
TOM: If you cut that open nicely, you can patch it nicely. There’s …
LESLIE: And then repaint and you’ll never know it was a …
TOM: And then repaint: retape, respackle and repaint. Yeah, it’s a project.
PAT: Yeah but what if you have to go back in again?
TOM: You shouldn’t have to go back in. It’d be nice – the perfect situation is when it backs up to a closet or something like that.
TOM: But if it backs up to a finished wall, OK. So you’re going to open it up, you’re going to replace the valve and hopefully you’ll be good for 5 or 10 years.
LESLIE: Yeah but Pat, if there’s a piece of – is there nothing on that wall? No piece of furniture? Not a bench, not an ottoman, nothing?
PAT: The cut would be right between two doors: one goes up to the attic; the other is a coat closet.
TOM: It’s not possible that any of that plumbing is behind the coat closet door?
PAT: No, we checked. We were praying.
TOM: That wall area? OK. Yeah, right, I bet.
LESLIE: Because an access panel can be as small as it needs to be. And you can get three or four of the same mirror or piece of art or objet-type (ph) thing to put on the wall and hang them vertically as a purposeful group and use one to conceal your access panel, in the event you ever need to go back in there, which you may never.
TOM: Now, listen, if you want to fix this, you’re going to have to open up the wall and replace the valve. After that, if you want to patch it, fine. If you want to install an access panel there, that’s fine. I’m sure there are a lot of things that you could put there that could cover that and make it less obvious.
But I am not the least bit concerned about you completely drywalling that wall back together again. Because even though it feels like it’s an enormous project, we’re talking about a half-a-day’s worth of work here to patch a wall, collectively. You know, patching it is very simple. You put one coat of spackle on, you come back the next day and put another one, another one and so on. It’s not that big of a deal to cut into a wall and replace it. Don’t let it dissuade you from doing this project the right way.
Pat, thanks so much for calling us at 888-MONEY-PIT.