Worcester 240 - Can't have CH without Hot water & vice v

[Grids]

Hi,

If I turn the hot water switch on (without necessarily running any hot water), the central heating also comes on.

Also if the central heating is on but not the water, I can still quite readily run hot water from the taps

It seems as though they can no longer operate independantly of each other.

Can anyone advise what the probplemn might be? A friend of mine armed with a mutlimeter seems to think I need a new circuit board, but I'm after any other suggestions.

Thanks

 

[Agile]

As far as I can tell your boiler is working fine but YOU dont know how its meant to work!

Be careful of "friends with multimeters". Any fool can buy one for £10 ! That does not make him a boiler engineer!

Tony

 

[Grids]

The boiler isn't working fine - I can't run hot water without the heating coming on. This isn't how it's supposed to operate.

 

[EliteHeat]

The boiler isn't working fine - I can't run hot water without the heating coming on. This isn't how it's supposed to operate.

Ha! I'm sure that Agile will appreciate that

I would have a look at your diaphragm. Unless of course you're a bloke and then I would have a poke around inside your diverter valve.

 

[Agile]

The boiler isn't working fine - I can't run hot water without the heating coming on. This isn't how it's supposed to operate.

Thats not what you said initially.

The rear end of your diverter is stuck!

It needs to be replaced. In theory it could be cleaned but commercially I would always replace the whole valve!

It only provides ONE function at a time! Either DHW or CH !!!

Tony

 

[bengasman]

Is your diagnoses based on control lights being on or do the rads get hot when you turn on the dhw?
If it is the latter, your diverter is stuck.
Forget your multimetered friend; I had a meter when I was 10, but certainly could not repair boilers until I was past my 12th.

 

[Grids]

This scenario might help explain further:

(Thanks for your help so far by the way)

1) Hot water and heating both switched off (pilot light obviously lit)
2) Then switch hot water on, but with no hot water being drawn
3) The boiler then instantly 'fires up' as if the heating has been switched on, or a tap has been opened. (Rads then subsequently get hot)

Does this confirm that it's the diverter or does it indicate something else?

 

[sooey]

That sounds like the hot water microswitch is stuck on.

 

[Grids]

Ah OK - any way of checking?

Is the microswitch easy to replace? will hit google again now....

 

[sooey]

To check it, disconnect it (you could just cut one of the wires going to it)and turn boiler on. Select hot water only, the burner shouldn't fire up. Easy to replace if you don't mind going onto the circuit board to make connections.

 

[Grids]

Thanks sooey - Ill check it out later