Luke Warm Water from Hot Tap

[Riley]

Due to the nature of the fittings it is not possible to isolate. (Builder was not the best - always cutting corners.)

There are isolating valves in the kitchen - but nowhere else. Not even in the bathroom sinks. And due to the nature of the shower mixer valves, we can remove the cartridges - but can't actually shut them off.

I guess my question is: "Do you think the most likely situation is that one of the mixer valves is the culprit?" - Because if that is the case I think I can identify which one based on the way the pipes flow.

In other words - The cold and hot have already mixed by the time they get to the kitchen and there are only 2 taps between the tank and the kitchen.

Again - many thanks.

I really hope I’ve misunderstood but you are saying your hot and cold mix before they reach the kitchen?? Hopefully that is via a tmv and not appalling piping??

The only way you are going to know for sure is to fit iso valves. I wouldn’t want to be changing taps on guess work

 

[tyzer007]

Below are photos of the shower mixer valve - with cover removed.

When we put a hand on the mixer with cover removed and turn on the sink tap we can feel (what we think is) water flowing through the mixer. I am guessing that there shouldn't be any water flowing through the mixer when the shower is off. - right?

 

[tyzer007]

I really hope I’ve misunderstood but you are saying your hot and cold mix before they reach the kitchen?? Hopefully that is via a tmv and not appalling piping??

The only way you are going to know for sure is to fit iso valves. I wouldn’t want to be changing taps on guess work

Sadly - you have NOT misunderstood

We took the sink and isolated the cold and just had the hot open. The temperature of the water leaving the boiler was 37C - by the time it got to the kitchen tap it was 16C - The only way that could happen was if there was mixing somewhere along the way.

Appalling piping? With this builder it's possible! (but I don't think so)

 

[Riley]

I think my friend you need to enlist a plumber. Builders build plumbers plumb

 

[SimonG]

A passing or missing check valve.

All sounds a bit heath Robinson.

 

[tyzer007]

I think my friend you need to enlist a plumber. Builders build plumbers plumb

LOL - Understood
What I meant was, "The builder" as in the company who employed builders and plumbers... most of which were underpaid...

 

[Stu-B]

Get them back if it’s not right

 

[Riley]

Sadly - you have NOT misunderstood

We took the sink and isolated the cold and just had the hot open. The temperature of the water leaving the boiler was 37C - by the time it got to the kitchen tap it was 16C - The only way that could happen was if there was mixing somewhere along the way.

Appalling piping? With this builder it's possible! (but I don't think so)

This is all sounding wrong. Your water isn’t heated in the boiler it’s being heated in the cylinder??

 

[tyzer007]

This is all sounding wrong. Your water isn’t heated in the boiler it’s being heated in the cylinder??

The water is heated through the boiler (plus we have an immersion heater)

My message above was not accurate. What I meant to say was that the water leaving the tank (after being heated via the boiler) is 37C. When I check just the hot supply (isolate the cold) at the kitchen sink it’s at 16C making me think that the cold has mixed with the hot before it gets to the kitchen.

Sorry for my sloppy message

 

[moonlight]

Has someone checked the non return in the shower? back flow issue