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No hot water to the tub

Recently, I have been unable to get a substantial supply of hot water to the main bath tub. Water pressure for the hot is very low, and substandard for cold as well. The bathroom sink is hooked into the same line as the tub; pressure is great there and I have no trouble with water temp on that faucet. Water pressure to the rest of the house (kitchen sink, dishwasher, master bath, washer, etc) is good.

I have checked all shut off valves, and they are all open. I believe this problem to be beyond my repair skills, but I would like to know if there is anything else I can try before calling in the professionals.

Thank you

Re: No hot water to the tub

Could you provide more info as to how the tub faucets are set up.

Is there also a shower connected to the tub.

Is there access to the water supply piping from the back of the tub, either thru an access panel, or otherwise,

Are there separate shutof valves for the tub hot & cold water supply piping?

Are the faucets on the tub separate, or combined in a single handle lever.

Is there a diverter valve.

Have you shut the water off & tried to take the faucets apart to inspect & clean them of any sediment or hard water deposits??

Many times sediment from the hot water heater, or from a hard water supply clogs up the faucet mechanisms, especially on the HOT side, & the faucets have to be flushed out, or taken apart & cleaned.

Any photos you can supply will be appreciated.

The tub faucets can be flushed in place if there is a separate shutoff valve for each faucet.

The hot water line is shut off, and disconnected or cut open between the HW shutoff valve & the HW faucet, a tight-fitting rubber or plastic hose is fitted over the line to the HW faucet, then the cold water is turned on to flush the HW faucet.

Please post back.

Re: No hot water to the tub

Without any more info, my first suspicion would be that you have a temperature balancing control valve...... and the balancing mechanism is currently locked up/stuck.

Sometimes these mechanisms are easy enough to take apart and free up......and other times you'd be ahead to just get a new/replacement TB assembly for the valve.

Re: No hot water to the tub

Thanks for the replies.

1. There is a shower connected to the tub. No hot water there either. Pressure is decent, but it is a economy head, so I think that helps.

2. There is no access to the water supply from the back of the tub, only from the basement, and that is only the shut offs.

3. There are seperate shut off valves for both hot and cold in the basement; for both the faucet and the tub/shower.

4. There is a single hand lever in the tub.

5. There is no diverter valve that I can see.

6. I have not tried to take the faucets apart for cleaning. We do have a water softner. Is it still worthwhile to take apart and clean if the water is not hard?

7. I have no photos, but can certainly take some.

The plumbing was done by the previous owner during a DIY remodel.

Thanks again.

Re: No hot water to the tub

The suggestion by goldhiller should also be checked to see if you have a temp balancing valve (also called an anti-scald valve).

Also don't ignore the aerator in the shower head (unscrew the shower head & clean the aerator).

If you find a temp balance valve & it is adjustable, see if you get any improvement by turning any adjusting valve open & closed several times.

The first step should be to establish that you have good water flow out of the HW and CW supply pipes.

Are these copper lines???

If you know how to solder, you can cut into the copper line to install a tee with a faucet on it in the basement between the shutoff and the upstairs HW faucet.

if you can't solder, you can install a saddle-type (saddle tee) faucet at the same point that doesn't require soldering (some towns don't allow saddle valves, some do); note the difference at the site below between a saddle valve & saddle tee; you want the one (tee) where you drill a hole in the piping & then add the faucet.

Slipping a hose over the cut pipe, you can check for full pressure & water flow on the HW line from the HW heater.

If you have full flow, you can then install the faucet valve, close off the HW on/off valve, open the faucet, attach a hose to a bucket, & turn on the cold water tap, turning the handle to "hot" so the CW flows full blast thru the HW fixture & out the new faucet into the bucket.

This type of back-flushing is highly recommended; it is very common to have small dirt particles & deposit buildups partially clog these fixtures because they have small openings.

If this fails, disassembling the tub faucets will reveal the type of faucet; cartridge types can be soaked in white vinegar for several hours.

The site below has several articles on this topic; enter "low water pressure" in the search box at the Ask the Builder site.



Re: No hot water to the tub

I would suspect that there's something in those lines between the sink and the tub,

perhaps the wrong diameter pipe?

perhaps sediment in the line?

My first place to work would be the handle in the tub. Replacing that might just solve your problem, whether you replace the whole thing or just a few parts.

So you can either cut into the parts past the shut off valves and check the water pressure past those valves or start at the other end and work back.

Re: No hot water to the tub

Thanks for all of the replies. When I get back home later this week I am going to start checking all of your suggestions.

I will report back on my findings.

Thank you,

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