Vaillant VCW GB 242 EH Central Heating no Hot Water

[pierce]

Hi,

I am having trouble with my Vaillant VCW GB 242 EH the Central Heating is working fine but there is no hot water.

There is a servo on it, which turns around and activates a micro switch to tell the boiler that water is flowing. The servo isn't turning around far enough to activate the switch.

We had an engineer out to look at it about a month ago and he changed the servo, after which the boiler would just about work, but it has got gradually worse until we now have completely no hot water again.

I have just taken the microbore pipes which connect to the servo, off and given them a clean but still we have the same problem.

The engineer that came out had never worked on a boiler of this type and was a bit unsure, so although I realise it was a fair assumption to change the servo, I am a bit hesitant about calling him back.

If anyone could provide me with any information about the likely cause of the problem I would be grateful



Please let me know if you need any more info.

 

[kevplumb]

assuming scale is not your problem

turn off water to boiler
drain

remove/ dismantle / repair / lubricate water section

View media item 26642

 

[pierce]

Thanks Kev, I am happy to give that a go.

Just out of interest do you know how a problem with the water section would affect the servo; I take it pressure from the water section makes its way to the servo somehow?

 

[kevplumb]

there is a pin connected to the water section that operates the servo valve

as you will see when you dismantle it

 

[pierce]

Think there might be a new problem here.

I have just forced the servo open to run a bath and the hot water is just luke warm????

 

[kevplumb]

why ask and then not listen

don't force anything anywhere that is really not going to help

clean and lubricate the water section before you do anything

worst it will cost you is a diaphram and about 45 mins of time

keep messing and the bill could well rise

 

[pierce]

Hi Kev, thanks for your info so far, its much appreciated you taking the time to help.

I was just adding another symptom, you used to be able to manually turn the actuator which gave you hot water, now the boiler is fireing but no hot water is coming out.

The servo that operates the microswitch sits on top of the water section, I removed the servo to remove a pipe before and didnt notice any pins connecting it to the water section, just a screw to hold it in place???

I will try and get a picture up.

 

[pierce]

Whoops, I see what you mean now

The huge pin that pushes the actuator


I just assumed that it was turned by pressure

I have the water section off just one bolt that holds the casing together is proving a bit troublesome to remove, just sprayed some wd40 on it, and will try again in a mo.

 

[pierce]

Its come apart now and the diaphragm is split Thanks for your help Kev, you are a superstar

 

[kevplumb]

yer supposed to say whats your adress to send the check to

make sure you get some silicone grease before you start reassenbling it

and clean everything

methinks you paid for a servo valve for nothing

 

[libby lou lou]

yer supposed to say whats your adress to send the check to icon_lol.gif icon_lol.gif icon_lol.gif


yer even spellin cheque like check, thought you was a brit

 

[pierce]

Cheques in the post addressed to;

Kevplumb
America

hope it gets there

Yeah looks like I didn't need the servo, nevermind. Can't blame the engineer too much, seems the servos do go wrong on this model.

Thanks again