Lukewarm water. Conflicting plumber suggestions.

[chrisjjr1980]

Hi, hopefully somebody can help with something that has already cost me a lot of money and still no further on.
Last December our shower was making a whistling noise and only delivering lukewarm water. We got a local firm to look at it and established that it was the diverter valve on the boiler. However, after fitting a new diverter valve they also decided to fit a new heat exchanger and flow sensor too. The water went back to normal for a while but then went lukewarm again. The water is lukewarm at all taps as well as the shower.
We then called our regular plumber and he decided that it wasn’t the boiler and more likely a shower cartridge. He thinks the cold feed will be getting into the hot feed at the mixer shower as this is the appliance that makes the whistling noise. I don’t get how this affects the other taps though? He wants £2000 to replace the cartridge and valve including a bit of plastering as he would have to go in the back via the stud wall.
I got a second opinion after him and another plumber has said it’s likely to be the boiler
and not the shower cartridge as all taps are lukewarm. I’m not sure how it will be the boiler as a lot of parts were just not replaced last year. The boiler is a valiant ecotec pro28 and is 11 years old.
I am in contact with another plumber who is highly recommended and feels that based on what I’ve said it is probably the shower cartridge and is sourcing a replacement.
I’m confused and frustrated as got so many different opinions. I don’t know if I need to just replace the boiler although I am reluctant to after splashing out almost £700 on it last year.
Any help or advice is appreciated. Thanks.

 

[terryplumb]

Isolate the cold water feed that goes into the boiler by the isolation valve on the boiler.
Turn electric supply to boiler off.
Turn on hot water taps/ outlets ,if water continues to flow from them there is cross contamination between cold and hot .
If all run dry it's a boiler issue.

 

[chrisjjr1980]

Thanks, I don’t know if it makes a difference but the central heating is fine

 

[terryplumb]

Makes no difference

 

[chrisjjr1980]

In layman’s terms why would a faulty shower cartridge make the other taps in the house lukewarm?

 

[dilalio]

Isolate the cold water feed that goes into the boiler by the isolation valve on the boiler.
Turn electric supply to boiler off.
Turn on hot water taps/ outlets ,if water continues to flow from them there is cross contamination between cold and hot .
If all run dry it's a boiler issue.

This will confirm it ^^^

 

[dilalio]

In layman’s terms why would a faulty shower cartridge make the other taps in the house lukewarm?

Because mains cold, and hot from the boiler join at the shower valve.
If the NRV is letting by at the shower, the higher pressure cold can and will push it's way up the hot pipe... Known as back feeding and will mix with hot water coming from the boiler. This will be felt at other outlets as a "blended" supply.

 

[chrisjjr1980]

Great, I get it. Thanks for the clear response. In that case will a replacement shower cartridge fix the issue or will we need a shower valve instead?

 

[dilalio]

Great, I get it. Thanks for the clear response. In that case will a replacement shower cartridge fix the issue or will we need a shower valve instead?

If you know the brand of the shower (guessing it's concealed) then contact the manufacturer for advice.
Failing that, you can try showerdoctor.com to help identify it and for advice.

Post a few photos of the valve to this thread. Might be able to ID it, branded gives you the best chance.

 

[dilalio]

Combi hot/cold crossover in shower mixer

Hi, a heating engineer came to fix my combi, but ended up concluding that there’s a hot/cold water crossover caused by the thermostatic valve in my shower (he checked the tsps and mixers on all the other basins ). However he ‘only does boilers’ so he didn’t want to touch the shower :rolleyes...

www.diynot.com

 

[chrisjjr1980]

This is the valve which is no longer available but the cartridges are

Premier JTY392 Pioneer Round Twin Shower with Built-in Diverter and chrome plated brass trimset Spare Parts

Premier JTY392 Pioneer Round Twin Shower with Built-in Diverter and chrome plated brass trimset Spares

www.divapor.com

 

[Stuckinarut]

When you run a hot outlet, does the boiler get to temperature fairly quickly on the front display or does it make noise at all?

 

[chrisjjr1980]

Gets to temp quite quickly about 71 on boiler but definitely not that at taps. No noise sounds normal.

 

[dilalio]

Gets to temp quite quickly about 71 on boiler but definitely not that at taps. No noise sounds normal.

Boiler is heating water but it's not getting away from boiler due to the backfeed so hitting temp in the plate hex very quickly.

Or you've also got a blocked plate hex.

 

[dilalio]

This is the valve which is no longer available but the cartridges are

Premier JTY392 Pioneer Round Twin Shower with Built-in Diverter and chrome plated brass trimset Spare Parts

Premier JTY392 Pioneer Round Twin Shower with Built-in Diverter and chrome plated brass trimset Spares

www.divapor.com

Need to see the manufacturers instructions as it may have NRVs that need cleaning /replacing.