Valiant Combi Boiler

[snaw]

Wondering if anyone can give me advice on a Valiant combi boiler (Old one) which is getting progressively worse.

Basically got problems getting hot water from it when I don't have the heating on.

If the heating is on the burners (Sorry for my lack of technical terms) fire up and we get hot water, no problem.

In the past it all worked fine, then this year, after winter ended and we turned heating off it sometimes worked without the heating on: the burners would fire up and we'd get hot water.

But now it seems like this never happens - occasionally fire up for a few seconds then they go off again. The boiler makes the whooshing noise it used to when it works, but when I check nothing is happening.

Any ideas what the issue is and what I should do to fix it?

 

[Agile]

Probably a 242 or 282.

This is a very common problem and is a failure of the diverter valve.

We always replace the whole valve so we can give a guaranty but some people just change the diaphragm or microswitch.

Bodgers sometimes adjust the switch to make it work for a few days after they get paid.

Tony

 

[ChrisR]

Probably a 242

But which?
Two square gauges on the right, or a black panel inside with bright green knobs?

Whot evva, you do probably need a diverter valve!

 

[Agile]

I was fooled last week!

I telephone identified a Vaillant with bright green knobs as a 242 but it was genuinely an 824 with bright green knobs! First I have seen with that and rather bright!

Tony

 

[ChrisR]

Das why I said black panel ... all the turbomaxes and tmax plusses have green knobs...

 

[snaw]

Hi,

Just had my missus check and it's a valiant VCW T3w (Also say's VCW-SINE...T3W)

Is changing the diverter valve something I could do myself - or the diaphragm or microswitch which you mentioned?

Guess I'm looking for easiest/cheapest option - we're getting our bathrooms done at the end of the year and we'll be getting a new Combi then so I'd rather not spend much cash on this if I can help it.

 

[Agile]

Thats a slightly different situation and I would say that it would be a two spanner DIY job meaning only for the skilled !

Its fairly straightforward for a professional but I would still allow about 1.5 hours as the parts involved can leak or be seized.

The indication is that the five pipe part in the middle underneath is not lifting the pin on the top to operate the microswitches. Usually thats because the diaphragm has failed but the pin also sometimes seizes in the gland.

Whilst removing it would be best to replace the diaphragm AND the gland.

Tony