Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 7/19/2017

My bathroom sink has no cold water only lukewarm when you turn the cold faucet

I have a interesting problem, my bathroom sink cold water tap has good water pressure and water flow but when you turn the tap it goes from cool to warm to hot rather quickly without ever touching the hot water tap.

When you turn the hot water tap initially the water that comes out is colder than the cold tap and then it warms up normally.

Any suggestion why its doing this, and how would one fix it?

Do you have the same question? Follow this Question

1 Answer


If a two-handle faucet (separate handles for hot and cold) then (assuming it does not flow hot water all the time due to a shot seat or seal), I would say your house is possessed.

1) Honestly, unless there has been some plumbing change (including possibly in neighboring unit if in a multi-unit building) recently which might have mixed up hot and cold lines, the only way I see this happening is if a tempering valve (which mixes hot and cold to provide warm water to the toilet tank to prevent sweating) has had a blockage so hot water in the mixing valve is backflowing to the cold line. If that is the case, presumably the toilet(s) served by that tempering valve would also be getting hot, not warm, water. HOWEVER, you said the "cold" water starts off cool, then warms up to hot - if the tempering valve were the problem I would expect it to start off warm, not cold - at least warmer than the surrounding cold pipes.

Also, if that were the problem, I would expect the cold water to any other uses in the same bathroom (shower, tub for instance) to also be warm then hot. (Some houses have one tempering valve, some one per toilet).

2) Remotely possible - this is a stretch but I have seen it, is the plumber was cheap (or done a long time ago) and instead of a tempering valve he just hooked hot and cold lines together at a tee leading to the toilet(s). Then, IF the normal cold line to the bathroom got clogged off, hot water might (depending on piping configuration) flow from the hot pipe through the tempering tee into the cold line, and backflow through the cold line to a tee leading to your faucet - so you would get warm (when stagnant) then hot water from the cold faucet.

3) If single handle faucet, then broken innards could also cause this - like a broken ball (which is connected to the handle and controls the water mix) letting hot water into the flow path at all settings, or a torn internal seal letting hot water to the outlet whenever the faucet is turned on. There is also at least one brand - I don't remember, I think it was Kohler but not certain, which has guide slots or ridges on the internal ball which controls what mix of water you get - if those wear out then the ball can rotate inside the faucet beyond the normal limits, meaning maybe both the cold and hot openings in the ball are exposed only to the hot water inlet inside the faucet, so you are getting little cold water flow.

4) Other possibility, also with single-handle faucet - has the setscrew or such on the handle loosened up, so the handle is turned/turning on the shaft so while you think the handle is set to cold and hot, it is actually hot and slipped to some position past hot ? You could remove the handle or feel closely at the shaft while turning the handle and be sure it is not slipping on the shaft (not possible on some brands because the shaft is elongated, not round).

5) To prove it is the faucet at fault, try running other water in the bathroom or bathroom backing up to it if any and see if full cold water comes out at any usage point (presuming they come off the same piping), or if the cold pipe near there (if accessible) is cold, not warm/hot. That could eliminate the "water" as the source of the problem and settle it on the faucet.

6) Another way - shutting off the cold pipe shutoff valve under the sink, putting a bucket under it, disconnecting the tubing to the faucet at the valve (a few ounces of watewr may drain out), then turning the shutoff valve on a bit and let it run a quart or two into the bucket to see if it changes to hot or comes out cold. If cold (or just a bit above room temp maybe due to proximity to hot pipes along the run) then full cold after it has run awhile, then the problem has to be inside the faucet, and a rebuild kit (replacing all wear and tear parts) should normally solve it.

7) Further to 6) - when you run the water various settings, one of the tubes/shutoff valves under the sink should be hot from the hot water running through it, and the cold one cold when cold water is run. If when running the cold faucet and you are getting hot water, if that tubing and valve gets hot, then you have an incoming water issue - crossed connections by a plumber (or neighboring unit) or possibly the tempering valve thing. If the cold tubing/valve stays at room temp (indicating no water flowing through it) or cold (indicating some flow) then the facuet is the problem.

Answered 3 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy