Valiant Boiler, can't get hot water to shower, but taps work

[jennieb108]

I've got a valiant VCW GB 242E. It's 7/8 years old.

We had a shower fitted last year and since the summer have been unable to get hot water through the shower, without first using taps to fire up the boiler. Even then it's a bit hit and miss as to whether the water stays hot, as the boiler then sometimes swtiches on and off.

We've got a service contract with British Gas, but they've been out 4 or 5 times replaced the diaphragm, fiddled about, but shower still doesn't seem to draw enough hot water to cause the boiler to light. They came again on Monday and it still doesn't work.

Came home this evening and the heating has also stopped working, although I can get hot water from the taps. The boiler seems to be on, but I looked at the gas meter and it wasn't moving.

Am getting so fed up of waiting in for hours for engineer, when they still can't seem to fix it. And in fact have now made things worse.

Any thoughts as to what might be the problem?

Thanks

 

[Rob]

draw 3 litres a min from your boiler at a basin or kitchen tap if it fires up and stays lit, then the fault cant really lye with the boiler. having trouble understanding why no one else can see this?

with regards to heating it could be many things unfortunatley. what happens when you try the heating from cold?

 

[chrishutt]

Any thoughts as to what might be the problem?

Yes -

We've got a service contract with British Gas

That's your problem. You need an engineer who understands how VCWs work.

 

[2face]

ditch the BG m8.

i have a customer who called them out twice .. both times failed to repair a simple fault . .!!

 

[ChrisR]

Recently:

Was paid to go across London again to change a diaphragm. Customer on 3* cover had already taken 3 half-days off work and BG had failed to turn up.

Was called to change a Diverter on a turbomax 242. BG had changed the diaphragm but wouldn't change the DV as "it would be sludge" causing the problem. It wasn't.

Was called to check a Puma. BG had left the thermocouple miles from the pilot , and had warned old lady customer that the boiler, "Could GO at any time", and she needed a new boiler.

Was called to a different intermittent Puma which BG3* man said needed a new main h/ex due to sludge, not covered. Temp measurements showed no evidence of sludge, but the flow switch was sticky, as usual.

BG aren't all bad, but there are too many of these.

 

[chrishutt]

I was recently called out to look at a shower that wasn't getting hot. The customer had already called out BG under 3* cover to check the Ravenheat combi boiler, but they had said it was fine and the problem was with the shower valve.

It took me 5 minutes to find that the boiler diverter valve was letting flow into the CH pipework when doing DHW. Simple diagnosis - just feel if the flow pipe gets hot while the boiler is in DHW mode. I advised calling BG back to change the diverter - it's a pig of a job with that boiler.

 

[cross thread]

if the diaph has been changed ,and u have enough water flow ,first check is the servo valve making its micro switch then is diverter valve moving to operate its switches, if this is not happening then either servo valve faulty.weep tubes to d/valve blocked.

 

[Agile]

Chris, why dont you come back from Cuba and settle somewhere nice like Bristol?

 

[meldrew's_mate]

There are, I think, three parts to the diversion circuit on the VCW; the water section, the servo valve, and the diverter valve.

there is a length adjustable link between the water section and the servo valve above it. This link could be badly adjusted, or semi-seized in it's guide bush. The servo valve could be buggered, the small link pipes blocked (rarely seen this), or the diverter valve (lower RHS of boiler) could be kernackered (even rarer).

As BG have had the water section out I suggest you concentrate your efforts around the link and the servo valve. Reach around the back of it and make sure it is returning under spring pressure, then the CH will start.

And finally, check the pump is pumping effectively, as this gives the motive power for all this to happen (must have clean impellor)

Just to get my dig in at BG, one of my customers pays me to diagnose problems so that they can tell BG what to do under the 3* plan. This saves them from several half days off work and the costs of the parts.

 

[jennieb108]

Thanks for advice. BG turned up this morning, fixed the heating and then turned it off (yes it was too warm in Bristol today).

Came home just now - heating not working again. Am going to get them back and show this forum, as they don't seem to have a clue.

Have told me it's a valve in the shower which handily isn't covered by my contract.

 

[jennieb108]

draw 3 litres a min from your boiler at a basin or kitchen tap if it fires up and stays lit, then the fault cant really lye with the boiler. having trouble understanding why no one else can see this?

Thanks for your reply:
I can get the shower hot by running the bath section of the valve, by turning it on and off until the boiler lights, then gradually turning the shower on. I'm going to get my plumber back, as it's less than a year old.

with regards to heating it could be many things unfortunatley. what happens when you try the heating from cold?

Nothing. Boiler comes on but radiators stay cold. Flame not alight, although does light when I run the sink tap. BG came this morning, cleared what they said was a block in small pipe, turned heating off again. Came home 20 minutes ago, heating not working again.

 

[jennieb108]

You need an engineer who understands how VCWs work.[/quote]

Yep, unfortunately, BG don't seem to have one. Fixed heating this morning, came home tonight, not working again!

Thanks for the advice though.

 

[chrishutt]

I hadn't noticed you were in Bristol. I cover west Bristol - any good? Maybe I could diagnose the fault for BG to fix? My email is in my profile.

 

[jennieb108]

I hadn't noticed you were in Bristol. I cover west Bristol - any good? Maybe I could diagnose the fault for BG to fix? My email is in my profile.

Thanks for that. BG coming back tom. PM and plumber coming to check the shower. If no luck will let you know. We're Bishopston, North Bristol.

 

[chrishutt]

I can cover Bishopston. Favourite trick of BG to blame shower for combi problem - see the example (in Cotham) I gave above.