Search the forum,

Main Combi 24 HE Flame Failure

Discuss Main Combi 24 HE Flame Failure in the Gas Engineers Forum area at PlumbersForums.net

S

Sandeep89

Gas Engineer
Messages
60
Hi Guys,

Got a Main Combi 24 HE which is stuck on flame failure. Customer had a gas leak on the gas run which was repaired, after this the customer turned the boiler on from the spur and the boiler is was stuck on flame failure which flashes slowly.

When hot water demand is given the pin hits the microswitch but boiler does not go through sequence. When heating demand is given the pin does not push out to hit microswitch, however I made manual contact to the heating switch and the boiler sparks but does not ignite and locks out.

I have checked pump by removing the bleed scre and pump is spinning, checked gas valve and getting 23mbar on p1.

Can anyone give me further guidance as customer is saying it only started with flame failure after gas leak was fixed. All gas isolation valves are open.

Thanks
 
Does the inlet pressure drop when it attempts to ignite? GV getting correct voltage? Have you checked resistance of GV? Smart meter? Credit meter? Any other gas appliances? - if yes, have you checked these?
 
Undertrained said:
Does the inlet pressure drop when it attempts to ignite? GV getting correct voltage? Have you checked resistance of GV? Smart meter? Credit meter? Any other gas appliances? - if yes, have you checked these?
Click to expand...
Hi

So inlet pressure does not drop when attempting to ignite.

They have another boiler inside the house along with a gas hob which are both working fine.
 
Does anything happen sounds like pcb if it’s stuck
 
ShaunCorbs said:
Does anything happen sounds like pcb if it’s stuck
Click to expand...
I can't hear the gas valve clunk or any sounds of it opening.

All customer has said they had a gas leak which was repaired as soon as the leak was fixed and boiler was turned on flame failure started flashing straight away.

Prior to the gas leak being fixed boiler was working fine. I had a look at the MI and it states the flame failure flashing slow is pump issue or internal fault.

I removed the bleed screw on pump and the pump is spinning.
 
Fan spinning ?
 
ShaunCorbs said:
Fan spinning ?
Click to expand...
Fan only spins when I make manual contact to the heating/pump proving microswitch, when contact to this is made the boiler reaches spark stage.

When hot water tap is opened pin pushes out to make contact to the microswitch at the front but fan does not kick in.

When heating is turned on the heating pin at top does not push out at all.
 
Pump or heating diaphragm need looking at as when the pump is running the heating pin should make contact with the micro switch
 
Undertrained said:
Would a diverter not making cause lockout though? 🤔
Click to expand...

Not sensing pump is spinning it’s a pump proving like the vaillants using the pressure sensor to check there’s an increase when the pump is on
 
ShaunCorbs said:
Not sensing pump is spinning it’s a pump proving like the vaillants using the pressure sensor to check there’s an increase when the pump is on
Click to expand...
Hi,

Come back here this morning turned heating on and pin still did not come out to make connection to pump proving switch. I made manual contact to switch and the burner ignited. Boiler ran for around 2-3 mins and then burner cut out and flame failure started flashing again.

Does it seem to be an issue with the pump. I am getting 230v at pump.
 
Hi Guys,

So replaced pump and both dhw and pump proving heating diagphrams.

The back pump proving pin still won't come out to make contact with the switch.

However if I make manual contact to switch burner fires up both on ch and hw.

Could it be a faulty diverter valve.
 
Also check the little 4-6mm pigs tail tube
 

Reply to Main Combi 24 HE Flame Failure in the Gas Engineers Forum area at PlumbersForums.net

Similar plumbing topics

Lou
  • Article
Plumber Who Worked Illegally Gets Suspended Sentence
A Plumber Who Worked Illegally Gets A Suspended Sentence After Falsely Claiming To Be Gas Safe Registered. A Plumber in Herefordshire was prosecuted after Hereford Trading Standards Team found that he was falsely claiming to be on the Gas Safe Register when he was not, putting members of the...
Replies
0
Views
192
Lou
Lou
F
What constitutes a Commercial Appliance and thus a Commercial Kitchen?
We run a community village hall and have a large kitchen provided for the use of hirers. This includes a Lincat SLR9 gas cooker which I believe is a 23.8Kw appliance with all six burners and oven on max. This was installed some 10 years ago and has passed all subsequent Gas Safety inspections as...
Replies
5
Views
494
FozzieBear
F
A
Emergency Stop Buttons in Boiler Rooms
We are from Alberta, and I own an electrical company. I have been asked by a BC Mechanical P. Eng. to install an emergency STOP button at the man-door to the boiler room. It's intent is to 'halt' the operation of the boilers in the room should there be an emergency. He is demanding that I do...
Replies
5
Views
274
oz-plumber
O
F
  • Question
No Hot water, Fixed and Broken Again Ideal Logic 24
Ideal Logic 24, Previous problem was that the hot water was only cold or barely warm if the heating was in use. If heating was off and boiler cold then would get hot water most of the time. Changing the flow cartridge about 2 years ago (when I moved in) solved this problem enough to suffer it as...
Replies
2
Views
147
Lou
Lou
Creating content since 2001. Untold Media.

Newest Plumbing Threads

Tiling Tools
Tiling Forums UK
DIY Talk
Tilers Forum
Tiling Advice Live
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock