Roman tub faucet, where is the mixing valve???

[Alice]

Hi,

We have a roman tub faucet and garden style bathtub. There is no hot water in it; meaning when the hot water is turned on, it runs cold. The plumber wanted to change the mixing valve and cut the fiberglass on the side of the bathtub, but didn't find the mixing valve there. Now he wanted to cut the ceiling on the first floor to see if the mixing valve is there.
Does anybody have any ideas where it usually is?

 

[havasu]

Who says you have a mixing valve? It is apparent you to not have that in this configuration. Try the bathroom sink adjacent to the tub.

 

[Alice]

Who says you have a mixing valve? It is apparent you to not have that in this configuration. Try the bathroom sink adjacent to the tub.

That's the plumber who says that the mixing valve should be somewhere underneath the bathtub. We will check the bathroom sink as you said. So the mixing valve would probably be there?

 

[Matt30]

Where I plumb from, it would be strange to have a mixing valve serving one fixture, and also have it not accessible. It would be a whole house ordeal.

 

[havasu]

You might want to check the other hot water faucets in the home. If all the other faucets in the home are receiving sufficient hot water, the problem is more likely caused by mixing valve issue nearby. Cross-connected pipes or a malfunctioning mixing valve can cause the tub to produce only cold water.

 

[Matt30]

Also, depending on what heats your hot water you may not have a mixing valve at all.

 

[CT-18]

The hot and cold knobs are where the mixing takes place. The supply goes into the handles and when opened they let out however much is needed to the faucet. You would only have a mixing valve on a single handle fixture like a shower valve, hot and cold flow in and moving the handle left or right controls the temp.

 

[Alice]

Also, depending on what heats your hot water you may not have a mixing valve at all.

The water heater which is installed in the garage heats the water for the whole house and I assume there should be multiple mixing valves in our system as there is a kitchen and a bathroom downstairs and two bathrooms upstairs, as well as a sink in the laundry room. The bathroom that has the problem has two sinks, a shower and a garden bathtub with roman faucet. Except for this bathtub, the hot water heats well everywhere else. In the bathtub it just runs cold from both hot and cold sides.

 

[Alice]

The hot and cold knobs are where the mixing takes place. The supply goes into the handles and when opened they let out however much is needed to the faucet. You would only have a mixing valve on a single handle fixture like a shower valve, hot and cold flow in and moving the handle left or right controls the temp.

Thank you! That makes sense. So what at your opinion might be the reason for only the cold water running from both sides in the bathtub?

 

[CT-18]

I am guessing somewhere in that bathroom a faucet is letting cold cross over to the hot side. It is just a guess, may need to get some boots on the ground over there.

 

[SHR]

Is there a single handle faucet anywhere in the bathroom?

 

[breplum]

turn off the cold supply at the WH. Does water flow out of the spout on the tub when the valve is opened?

 

[Alice]

Is there a single handle faucet anywhere in the bathroom?

Yes, there is a shower in that bathroom with a single handle.

 

[SHR]

Replace the cartridge in your single handle shower faucet and your problem will be probably be solved. Also, your "plumber" doesn't seem to have a clue. Do not let that "plumber" touch your plumbing.

 

[havasu]

See if this helps you understand the issue you may have....

https://www.thisoldhouse.com/how-to/how-to-repair-shower-anti-scald-pressure-balancer