ittermitent fault in ch

[zcat]

hi I have a vaillent vcw gb 242 and just had the expansion vessel changed as it was knackered ! was working fine after it was changed.
Now the hot water works fine but the central heating is really problematic 9 times out of 10 it wont come on the fan starts but the pump and the gas dont so no hot water flowing thru the system. this started happening 1 or 2 days after the expansion vessel was changed
my plumber said ask here and let him know what happens as when he came round it did work fine after not working for a week
any ideas anyone
thanks

 

[bengasman]

has the turret been off?

 

[zcat]

has the turret been off?

hmm whats the turret (txted my plumber and he asks)
thanks

 

[zcat]

OK so my plumber left a while ago to go to another job as it was working fine.
So I left the boiler on to see what happens, normally I only have it on for 1 hour in morning and 1 or 2 in eve (too expensive to run all the time) this keeps the house not too cold as im on a low income.
Now its gone back to just the fan running with nothing else happening which is really annoying the thermostat on the boiler is on 5 (no thermostats in house) and the temp gauge is now down to 0 its using electricity to drive the fan and not producing anything.
This is just murphys law aint it

 

[zcat]

has the turret been off?

No its not been off

 

[gas_man_gaz]

bet the diverter valve isnt makin the microswicth for the central heating, is ya hot water ok?

 

[zcat]

bet the diverter valve isnt makin the microswicth for the central heating, is ya hot water ok?

yup hot water works fine

 

[gas_man_gaz]

if ya luk to the right hand side of the boiler, there is a diverter valve with a clear top on. wen ya operate the hw the assy should move out and make a microswitch and wen ya got ch on it should move inwards and make another microswitch for ya heating

 

[bengasman]

are you sure the fan works but not the pump?

 

[gas_man_gaz]

iam presuming the pump is workin

 

[bengasman]

iam presuming the pump is workin

is wot I thought innit, like

 

[gas_man_gaz]

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