baxi 105e no pre heat.

[desrob]

the boiler goes through the lighting sequence,sparks but will not allow any gas through,what holds back the gas on this model no mi

 

[bill577]

check that you have 240v across 2 and 4 on a1 on the pcb, this is the connection for the gas valve coil, if its sparking the coil should be open allowing gas through.

 

[desrob]

check that you have 240v across 2 and 4 on a1 on the pcb, this is the connection for the gas valve coil, if its sparking the coil should be open allowing gas through.

thats what i thought,i'll test for 240, if coil not energizing and remaining shut,will the complete gas valve need replaced

 

[diamondgas]

It depends on the model desrob. At some time, I think it was the HE but may have been on the 105E instant too, they introduced a wave converter in the molded plug of the gas valve. To be certain check the coils on the valve for resistance IMO

 

[desrob]

It depends on the model desrob. At some time, I think it was the HE but may have been on the 105E instant too, they introduced a wave converter in the molded plug of the gas valve. To be certain check the coils on the valve for resistance IMO

what resistance should i be looking for.

 

[diamondgas]

Well you're always loking for some, better than none at all ... lol Usually you'll find infinate or there abouts if there's a problem .. If the valve has 5 prongs then the middle one's the earth and the two either side are individual coils if I'm not mistaken! I'm talking in generic terms here Desrob not specific to the boiler you may have yeh

 

[desrob]

Well you're always loking for some, better than none at all ... lol Usually you'll find infinate or there abouts if there's a problem .. If the valve has 5 prongs then the middle one's the earth and the two either side are individual coils if I'm not mistaken! I'm talking in generic terms here Desrob not specific to the boiler you may have yeh

yeah no problem,point me in the right direction,and hopefully i'll do the rest.thanks as always.

 

[diamondgas]

yeah no problem,point me in the right direction,and hopefully i'll do the rest.thanks as always.

Reason I quiery the valve is that you mentioned "pre-heat" That was introduced on the 105e combi instant and then the HE. I'm nearly sure they involved the wave converter plug? maybe someone else here can confirm or reject that? I carry a lead as stock to rule it out to be honest

 

[desrob]

Reason I quiery the valve is that you mentioned "pre-heat" That was introduced on the 105e combi instant and then the HE. I'm nearly sure they involved the wave converter plug? maybe someone else here can confirm or reject that? I carry a lead as stock to rule it out to be honest

i mentioned the pre heat, as when 105e are mentioned the normal response is to ask whether it's the pre heat model or not,mine has not got the pre heat function,i can't seem to get my head around the start up sequence,at what point does the gas valve open.?

 

[diamondgas]

Gas valve opens once the pump and fan have been established and the boiler temp is below what the thermostat's are set at! IF you're getting no spark then check resistances throug the pump flow switch as well as the APS... Any flashing lights on the front?

 

[diamondgas]

i mentioned the pre heat,

Just realised I read your post heading totally wrong :banghead: I thought you mentioned there was NO pre-heat occurring! LOL

Silly me

 

[desrob]

Gas valve opens once the pump and fan have been established and the boiler temp is below what the thermostat's are set at! IF you're getting no spark then check resistances throug the pump flow switch as well as the APS... Any flashing lights on the front?

flashing no flame light,i have a good spark,this is what makes me think the gas valve is not energizing

 

[Billy Bob Bob]

Reason I quiery the valve is that you mentioned "pre-heat" That was introduced on the 105e combi instant and then the HE. I'm nearly sure they involved the wave converter plug? maybe someone else here can confirm or reject that? I carry a lead as stock to rule it out to be honest

yep all now use the converter plug

 

[Billy Bob Bob]

flashing no flame light,i have a good spark,this is what makes me think the gas valve is not energizing

your gas valve has failed

 

[diamondgas]

I'd totaly agree desrob
I'd be thinking the same ... as said check that you have the power suplied to the valve, 2&4, if so then it's the whole valve needing replacing I'd say! Check the coils to be sure if for no other reason than your own assurance !

 

[diamondgas]

yep all now use the converter plug

Cheers Gas man

 

[desrob]

thankyou . diamondgas, and gas man. you have reassured me and pointed me in the right direction yet again

 

[diamondgas]

Your welcome ..

Let us know how you get on

 

[diesel_ltd]

great advice there lads, i take it desrob you have checked gas supply and that the gas valve isolation tap is open not trying to teach you how to suck eggs mate but sometimes we jump in at the deep end

 

[desrob]

great advice there lads, i take it desrob you have checked gas supply and that the gas valve isolation tap is open not trying to teach you how to suck eggs mate but sometimes we jump in at the deep end

i did, but your right in mentioning it as some times the obvious is forgoten about,

 

[Poxi]

Make sure Min and Max BP`s are set up or you will cook her

 

[desrob]

Make sure Min and Max BP`s are set up or you will cook her

ok poxi, i'll do that.