Vaillant Boiller ignition problem on start up

[pearcie bloke]

I have a Vaillant turbo max VUW 282/1 E boiler. on start up the ignition indicator light flashes and boiler does not fire. does any one know what this fault is or what it indicates? The fault was intermitant and cleared a few times with reset but is now will not clear after reset. I've had Corgi boiler engineer come out and he checked the fan and air pressure switch, all fine, he thinks it may be one of the the PCB boards. Board(s) will cost £120 +VAT alone but he's not 100 percent sure its that!
Any help will really be apreciated before I spend £200.

 

[kevplumb]

have known the odd gas valve go west

 

[Agile]

Any competent boiler engineer would have checked to see if the gas valve was being powered.

If its powered and gas supply present then its faulty.

Next test is resistance of solenoid coils.

I am not very impresed with your CORGI !

Perhaps you need a better one?

Tony

PS did he check the o/h stat. Chris will remind you about that one! You copuld probably do that yourself if you cut the power!

 

[BOB.ELOD]

Any competent boiler engineer would have checked to see if the gas valve was being powered.

If its powered and gas supply present then its faulty.

Next test is resistance of solenoid coils.

I am not very impresed with your CORGI !

Perhaps you need a better one?

Tony

PS did he check the o/h stat. Chris will remind you about that one! You copuld probably do that yourself if you cut the power!

yea need 0.5 ohms resistance on the solinoid if not change.

 

[Agile]

I dont think anybody should do that!

 

[ChrisR]

yea need 0.5 ohms resistance on the solinoid if not change.

Eh? You wot??

Tony the /1E doesn't have the infernal overheat stat.

 

[kevplumb]

errr glycol springs to mind had a spate of sticky gas valves up here a while back

that stuff sticks like **** to a blanket

 

[pearcie bloke]

Thank you all for your quick response. my engineer is bringing the PCB boards tonight but I will ask him to check the gas valve first as per you comments! I will keep you informed of the out come. Thanks again! I will talk to him about about the PCB he has ordered! Dont think I should pay for it!
Lets hope its the valve. I guess that will not be as expensive!

 

[pearcie bloke]

Had a reply from valliant they thought it was the ignition transformer or the gas valve. Engineer came out last night with new PCB's changed them as the ignition leads come straight off the board, checked the transformer voltages in and out, all ok. Boiler still did not fire! He thought that the pressure differential switch over the pump, (not sure what its called) was not rising enough, so he forced / wedged it to make the contact and it fired straight away! He said it may need a new switch / diaphram and left it open with me to check that the pump and water pressure ar ok befor start up. as this is the fail safe if no flow or water. Untill he can get a new one the weekend. On timed start up the same problem happened but after reset it fired straight away.

The pump has a two stage switch and about a month ago I changed it from possition 2 to 1, 1 been the slower speed because the TRV's where giving a louud whistle. All the rads where still getting hot in possition 1 on the pump. It had been ok for a few weeks but could this be casing the problem and I just need to switch the pump back to possition 2. It said in the manual possition 1 should be ok!