potterton mf 80

[kennif]

Hi, potterton mf 80 will not fire up.
history; voltages to pl3 and pl1 intermittant, unknown cause.
voltages at pl1-3 return, flow chart points to gas valve, pilot solenoid open circuit (v1)
fit new gas valve (vk4100t) Voltages at pl1 pl3 low.
pcb inspection, all appears ok.
Next morning refit aps, (I previously bridged pressure switch to eliminate but voltages still low.) voltages reappear.
power to plug at gas valve, new valve, fan running, it has to start. NO, DOH!
Check gas supply,ok.
ignitor sparking, no gas from gas pilot outlet. remove pilot pipe, no gas from valve, pilot solenoid cannot be opening.
Can this be a new valve being faulty.(flow chart says with required volts to valve if no ignition/pilot change valve)?
Can the pcb be causing no pilot gas?
What are the resistance figures for a healthy gas valve (vk4100t)? I have .9 at v1 and v2 ie both solenoids. What should I get across pins 1 to 5 ?
This is probably a well known fault with this old potty (1999) I don't want to buy a pcb and another gas valve and find it still wont work. (shop declined to take back new gas valve, well it may not be faulty.)
Please help if you can. ken

 

[gaswizzard]

Not surprised shop won't take gas valve back , get it checked by someone who will sort the problem , bridged APS?

 

[45yearsagasman]

You, my friend are walking on dangerous ground. You are obviously out of your depth. No advice from me other to get your boiler repaired and checked for safety.

 

[Dan Robinson]

Amazing innit

 

[kennif]

Hi, potterton mf 80 will not fire up.
history; voltages to pl3 and pl1 intermittant, unknown cause.
voltages at pl1-3 return, flow chart points to gas valve, pilot solenoid open circuit (v1)
fit new gas valve (vk4100t) Voltages at pl1 pl3 low.
pcb inspection, all appears ok.
Next morning refit aps, (I previously bridged pressure switch to eliminate but voltages still low.) voltages reappear.
power to plug at gas valve, new valve, fan running, it has to start. NO, DOH!
Check gas supply,ok.
ignitor sparking, no gas from gas pilot outlet. remove pilot pipe, no gas from valve, pilot solenoid cannot be opening.
Can this be a new valve being faulty.(flow chart says with required volts to valve if no ignition/pilot change valve)?
Can the pcb be causing no pilot gas?
What are the resistance figures for a healthy gas valve (vk4100t)? I have .9 at v1 and v2 ie both solenoids. What should I get across pins 1 to 5 ?
This is probably a well known fault with this old potty (1999) I don't want to buy a pcb and another gas valve and find it still wont work. (shop declined to take back new gas valve, well it may not be faulty.)
Please help if you can. ken

I am only asking for the resistance or voltage figures for a vk4100t gas valve to ascertain if the new valve is serviceable before I call in the gas man who installed and serviced the boiler for years. (he lives in my road)
If the new valve is faulty then shop will take it back.
I have read on forums that a faulty gas valve will, quote; blow the pcb.
Any thoughts on this?
I need to give my gas man a heads up before he does what most installers will do; change components till it either works or it comes to the point where it would be more cost effective to change the boiler, bearing in mind I intend to have a new boiler installed (re-sited) and new plumbing when we have a new kitchen and ensuit bathroom installed.
Thank you for your safety concerns. There are some areas where DIYers should stay clear of. I totally agree. However; I worked as an instrument technician at B.P. research center working with gas, gas detection systems, electricity/electronics and some very volotile substances. I managed to not electrocute myself or blow up Sunbury on Thames.
Regards ken.

 

[mickyg]

However; I worked as an instrument technician at B.P. research center working with gas, gas detection systems, electricity/electronics and some very volotile substances. I managed to not electrocute myself or blow up Sunbury on Thames.
Regards ken.

so as a gas engineer would you trust me to come to your workplace and have a go at fixing some of the equipment you deal with ?