How best to safely control hot water to a bathroom faucet?
April 14, 2014 11:41 AM   Subscribe

How can I control hot water to a bathroom faucet (tap)?

I live in a 70s highrise. The hot water is extremely hot. I tried turning down the shut off valves. The hot water one is so hot that I have to use a cloth to turn it. If I turn it down all the way, I only have cold water. Even the tiniest move means I can access scalding water.

I have a young son who was traumatized by a hot water burn at a playpark. (We settled out of court.) While we continue to address his needs around that, I'm going stircrazy from having to set the water for him every. single. time. he needs to wash his hands.

I would like to get either a water mixing kit or a thermostatic faucet or something else. I would prefer not to spend money unnecessarily and a DIY option is worthy of consideration.

I've been to a well-known plumbing store here in town, where I received horribly condescending service, which honestly felt like sexism was at work. I have also been to Big Box stores, where the service was very helpful and they knew what I needed, but didn't know were to send me, since they don't carry it. They told me they used to a carry a kit that you could attach, but now all they have are mixing valves, which would involve a plumber.

Daycares here in Vancouver often have a water mixer, so I know there's something you can attach to a faucet to make sure the water is safe. Front line staff don't know where these come from.

I could also consider a thermostatic faucet, but they seem to be commercial and even the plumbing supply place (which was so rude that I won't return) doesn't usually carry them and couldn't even really explain it to me, plus it was a commercial faucet.

**Asking the building to turn down the heat isn't an option.** People on the top floor won't have hot enough water and they need enough hot water during times of high demand.

And, while I prefer to keep costs down, I am willing to spend to get what I want.

This is in Vancouver, Canada.

posted by acoutu to Home & Garden (16 answers total) 3 users marked this as a favorite
There are google hits all over for anti-scald valves.

While many of them are there to prevent the "flush-of-death" problem in the shower (sudden drop in cold water pressure from a toilet-flush makes the shower temp skyrocket), the application appears to more universal. Lowes (big box) lists at least one, and honeywell lists many. All purchaseable over the internet, ~$100 usd.

Installation is another matter and seriously depends on your plumbing and what's allowed/allowable/do-able in your building. Yet this one claims it mounts on your sink (aerator), not on the pipes, though I am not sure how universal aerator threading is across sinks.
posted by k5.user at 11:53 AM on April 14, 2014

What you're loooking for is a mixing valve, like this one. It would be very easy to install yourself at minimum expense.

Sinks usually have 3/8" incoming hot water and cold water connections. You would disconnect the flex hose going to the cold water and the one going to the hot water. You'd add a t-fitting to split the cold water into two lines, one of which you'd feed into the sink, just like before. The other of which you would connect along with the hot water line to the mixing valve (as labeled). The outgoing from the valve, you would connect to the hot water inlet on the sink using another flex hose. Once this is done you can dial in the temperature you want for your hot water by adjusting the valve.

In this hypothetical example, you'd be looking at a total cost of less than $75. I realize you are in Canada, but even if you had to go metric, the principles would be the same and the parts should still be easy to find.

I actually just hooked one of these up in my downstairs powder room. This is the sink where my five year-old usually washes his hands and the water lines come from right next to the hot water heater, so the hot was always boiling hot. He burned himself once and was on the verge of refusing to wash his hands ever again until I put a mixing valve in. Since then, he's happy and--best of all-safe.
posted by DirtyOldTown at 11:54 AM on April 14, 2014 [1 favorite]

Also: I should have mentioned that undoing this modification to your sink would be easy as well, so if/when you needed to move, you'd have only a few minutes' work to put it back like it was before.
posted by DirtyOldTown at 12:04 PM on April 14, 2014

Response by poster: K5.user, I have been all over Google and have not neglected to use the Internet. I am looking for an easy-to-use, easy-to-install best value answer that does not require me to guess at what devices work or have installation challenges. Thank you for understanding.

DirtyOldTown, thanks. The guy at Home Depot told me I'd never be able to install one of those valves without a plumber. They told me I'd need a kit with parts already assembled. Do you think it's just that I need the t-fitting and flex hose? Does it seem like something a single mom with no plumbing experience could do or would I be better to get someone? It sounded relatively okay-ish from your description. Maybe the Big Box store guy was overly dramatic? I do some minor home renovations (mostly demolitions!) on my own, but I've never done plumbing.

Note: I don't love my faucet or sink, so would not be opposed to a faucet-based solution.
posted by acoutu at 12:04 PM on April 14, 2014

Do you have separate hot and cold water taps, or do you already have one spigot and two handles?
posted by Ruthless Bunny at 12:08 PM on April 14, 2014

Can you address this with the building manager? Explain you're concerned about scalding and see if they'll have a plumber install the mixer that DirtyOldTown linked to.

Most buildings have trades-people in once a week or so, it's a relatively cheap part and if you explain that your son has been scalded before, and that you need it to feel safe considering how hot the water is directly out of the tap, I doubt seriously that you'll encounter any static.
posted by Ruthless Bunny at 12:14 PM on April 14, 2014

If you want to temper the water temperatures for your entire house, yeah: you'd need a plumber. For one sink, so your kid can wash his hands in comfort? Easy. Couple of crescent wrenches and twenty minutes, tops.

While I strongly suspect than Canadian sinks use the same size (3/8") connections as generic American ones, I can't be sure from here. What you can do though, would be to shut off your hot water underneath the hand sink in question and disconnect the braided metal hose underneath that brings in the water. Take that to a hardware store and verify the size of the end that connected to the water supply. It should be 3/8". All of the stuff I found on Canadian hardware stores online was 3/8, so I imagine it is.

All you should need is a mixing valve ending in compression fittings (compression=they just twist on, basically), the t-fitting, and two of those 3/8" to 3/8" braided hoses.

This is all just stuff you'd be twisting into place with wrenches below the sink.
posted by DirtyOldTown at 12:16 PM on April 14, 2014

DirtyOldTown's suggestion of using a braided pipe is about as easy as it can get.

But, since we don't know your current plumbing situation and you admit no experience, you may be best served via a professional as Ruthless Bunny suggests via the supe or recommendations from neighbors. Be direct : "I want a anti-scald on this faucet so we won't scald our hands". No need for back story.

(eg: if it's 1970s, odds are fixed lines run to the sink rather than any nice flexible hose, and there may or may not be individual shutoffs under the sink or easily accessible. If there are shutoffs, do they still work/turn, and can whatever line is there be removed, or is the line crusted over and can't easily be unscrewed from shutoff ? etc etc. That's why I linked to an aerator - worse case is you butcher the finish on the existing sink to get the old aerator off, as they gunk up/crust on very easily vs worst case of leaky leaks mcleakerson)
posted by k5.user at 12:26 PM on April 14, 2014

Usually there are building codes prescribing the maximum temperature of hot water at the faucet, although some quick research shows that Canada codes used to be at 140F (too high, will still scald) and new code changes to lower it to 120F at faucets were introduced but may be on hold....

I recommend first measuring the temp of hot water at your faucet (a meat thermometer will work), then stopping by your local city office to find out what the actual building code requirements are for maximum hot water temps at the faucet for your situation (apartment-type building).

If the code requirements for existing structures (not new construction) dictate lower temps, you should be able to get a code violation written for your building (usually requires an onsite visit from an inspector) and the building owners will have to solve the problem, somehow, on their own dollar.

You're a tenant, and providing a "safe" living environment is the responsibility of the owners.

OTOH, if the faucets to do comply with code then you'll need to do as others have mentioned and install your own temp mixer below the faucet.
posted by jpeacock at 12:37 PM on April 14, 2014 [1 favorite]

Two clarifying questions:

1) Do you want the fix to affect all faucets in your apartment, or just a single sink?
2) Do you own or rent?
posted by barnone at 2:11 PM on April 14, 2014

Response by poster: Thanks, everyone. I own, so I think I'm probably responsible for the water coming into my suite, although I will check the temp.

I have a single tap, but I'll look under the sink and confirm about hoses when I get home.
posted by acoutu at 2:42 PM on April 14, 2014

Canadian Plumbing fixtures are the same as the US.

DirtyOldTown's homedepot links are throwing an error for me but his procedure is good.

It would be unusual for your lines to be hard piped to your taps but not unheard of; a picture of your under sink area would be helpful. Though if it was hard piped the solution would be straight forward as you could use sharkbite fittings to install a tempering valve with just a tubing cutter.

However if you have standardish for 1970 3/8ths soft drawn copper tubing leading to your tap (could be chromed) then this Under Sink Guardian Thermostatic Mixing Valve is the sort of thing you need to fix your problem. Watts says their distributor in BC is Con-Cur West Marketing. They are located in Coquitlam but they might be able to point you to a local store that stocks or can order this valve. Installation would require only a couple wrenches (even crescent/adjustable wrenches) and a tubing cutter and possibly new tubing running from your faucet to your sink if there isn't enough slack in your supply lines. This valve will also work with 3/8th plastic tubing. If you have the "braided" supply lines then the simplest thing to do would be to change them out for plastic supply lines so you could install the valve.

Watts also has a thermostatic lavatory faucet though installation would be more involved and they are sort of commercial looking (and probably carry a commercial price).

I find home depot reps to be mostly useless for this kind of thing if they don't have it (and sometimes when they do) but home hardware people are often willing to work with you to order stuff in. Bring a printout of what you want (the watts mixer I linked to) and see if they can find it if the distributor isn't helpful.
posted by Mitheral at 8:22 PM on April 14, 2014 [1 favorite]

Response by poster: Thanks. I took a look under the sink again. It is all hard materials - no flexi hoses. Cutting tubes and things sounds beyond my skill set.

I tried turning off the hot water and then the faucet started to leak. I am not sure if that is norml, but it made me wonder if the faucet is part of the problem. My other two faucets are not as hot, although all three will get up to 140F on my meat thermometer.
posted by acoutu at 11:35 PM on April 14, 2014

> Cutting tubes and things sounds beyond my skill set.

Unless you have a moderate amount of experience soldering other things - jewelry or circuit boards - I would not recommend you try to do this.

And, no, it's not normal for the sink to leak when half the water supply is cut. Replacing the fittings on the faucett -beginning with just the washers - might be an easy fix. I wouldn't count on it, but it might.
posted by IAmBroom at 9:23 AM on April 15, 2014

Response by poster: Thanks. Do you think this would work?
posted by acoutu at 11:29 AM on April 15, 2014

Can't hurt to try.
posted by IAmBroom at 9:24 AM on April 16, 2014

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