Worcester 28cdi problems?

[Benty666]

Hey room this is my first post and I'm pretty numb when it comes to this stuff so any and all help will be much appreciated.

I just bought a house and have discovered a problem with the boiler/hot water. I own a worcester 28cdi boiler and seem to have a problem getting scalding hot water from the bath and shower. The hot water from the kitchen taps is great but the bath is probably a maximum of 40 degrees and the shower maybe 35 degrees. The shower is a bristan pisa mixer.

If anyone has encountered similar problems or know what may be wrong with my boiler then please let me know. If you require any more information please ask. I want a hot shower.

Thank You

Chris

 

[superdupergasman]

slow the water flow from the bath and try that??

 

[Benty666]

Yes unfortunately I tried that and the water temperature remained the same. However, I did notice earlier today that the bathroom sink, sitauted right next to the bath, has scalding hot water.

Is it possible that there is a blockage in my shower/bath pipes that is preventing my water from getting hot?

Thanks

Chris

 

[namsag]

measure the flow rate at bath tap it should be approx 12 litres a minute and raise the incoming water temp by 35 degrees C.
If right amount of water check that the actual gas pipe to boiler is not any smaller than 22mm,
Also take front cover off boiler and with tap running look at flame through site glass it should remain fairly high throughout demand if it drops down and water not particularly hot this would suggest plate heat ex partially blocked , but could also be a sensor fault.

Seems strange though that sink tap will get roasting but even bath tap cut right down will not , not by anychance got some sort of thermostat mixer valve between hot and cold to bath.

Worn diaphragm can sometimes stop a bath coming on but will allow a sink to come on , not unless your diaphragm is that worn its causing pushrod to bounce (so to speak) on micro switch to bring burner on and off.
Strange one

 

[Benty666]

Ok Thanks.

How would I raise the water temp by 35 degrees? The water switch on my boiler is already on max.

Also can I assume that your theories on my boiler are quite expensive to repair?

Thanks again

Chris

 

[Agile]

Isolate the cold water inlet to the boiler and see if any hot water comes out of the hot taps.

Turned off at the boiler NOTHING should come out of any hot tap. If it does then you have a crossover, this is most often in a thermostatic shower.

Tony

 

[namsag]

You dont raise it 35 degrees, that is what the boiler is designed to do when it is working as it should with the right amount of water passing through it

 

[Benty666]

Your gonna think I'm taking the mick now but how do I isolate the cold water supply. I apologise for this but I really am numb when it comes to this stuff.

Thank You

Chris

 

[Benty666]

When you say isolate the cold water supply, do you mean turn it off at the stop cock? Or is there any way? Sorry I know I'm being a pain.

Chris

 

[Agile]

No! You must still have a supply to the cold taps for the test to be effective.

Under the boiler there is a valve to turn to just isolate the cold water in at the cold connection under the boiler.

Tony

 

[Benty666]

I'll have to download the instructions for my boiler cause I can't seem to find what you are discribing. Does the valve have a particular name like isolating valve or something? Or does it look different from the other valves?

Chris

 

[clf-gas]

Chris,

looking at the boiler from the front, trace the 15mm pipe (2nd from right) to where it enters the boiler. Here you will see a brass fitting with a little piece that will take a slotted screw driver, turn this one quarter turn.

water to boiler will now be issolated, turn on hot tap and seeif it runs continuously.

 

[Benty666]

Ok Thank you.

I'll try that when I get home

 

[nickso]

be aware there is a high chance the isolation valve will leak if you use it. they can be a bugger to change as well.

 

[Benty666]

Ok well lets remember I'm not the most confident person in the world when it comes to this stuff so I think I may get a plumber out.

I just can't understand why the bathroom sink gets scalding hot water when the bath and shower located 6 inches away from it are only getting warm water.