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Boiler Breakdown Sticky

bright spark said:
Here's 1 for commercial oil burners. I'd say Croppie's seen this. Have seen this happen a couple of times on Riello RL burners.
If the plant room door is open on a sunny day, sun shining in can make d burner go to lock out.
Photocell can pick up light shinning down boiler sight glass, say when boilers up to temperature, photocell picks up some light, the panel thinks there's a flame like a big lump of carbon on d head burning, and locks panel out.
You'll go out on call, Murphy's law it'll be a dull day and there'll b no apparent fault.
Click to expand...

Don't it throw you! Bit of insulating tape, job done.
 
Vaillant ecoTecs

If you have random unrelated intermittent faults.
Get a cuppa turn it on heating and watch the display. If the boiler flow temperature jumps around from say 55 to 62 and back in the blink of an eye the PCB needs replacing. It can take 5-10 min to start doing this.

Video on next post.
 
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Vaillant EcoTec Plus - if you fit an external expansion vessel make sure it goes on the return! Had a nightmare with one today, kept getting F75 (no pressure increase when pump spins). Eventually found out it was because I'd fitted the expansion vessel on the return - NEVER AGAIN!!
 
Glowworm hxi model - when they turn off after being constantly in use they may show f5.
Overheat stat needs to be reset normally looks red and is located near the top left
 
Turned off and drained down an arriston microgenus to find on re filling and powering on the fan wouldn't spin.
Checked voltage to fan = nada, assumed PCB. Was about to go buy PCB before remembering the main circuit flow switch needs to make before your get fan/ignition.
Air in diaphragm - bleed pump = save your self a fortune and embarrassment.
 
Another one iv had a few of recently is a blocked condensate rubber tube on the greenstars (cubed trap not the bottle) - give it a squeeze and work it out. And of course wash it through with some water
 
Ariston Microgenus He fault code e34, MI's say APS not making. If the boiler fires up when you take the inner case off then you need to remove the restrictor ring in the flue. Spoke to a Ariston engineer on a product training day who told me to undo the flue elbow and remove the restrictor ring as it's not supposed to be there and it actually worked.
 
abc_plumb said:
Biasi M96(24/28)SM/C2
Round black APS
boiler fires up for a few seconds then goes off, continues to spark. After a few attempts the lock out led comes on. Works when the combustion chamber is off.

check flue was fitted correctly as the white seal bends when pushing the elbow into the flue and doesn't sit right.
Fault only starts after the warrenty period is over 🙁
Remove the complete flue clean and pour water in the top of the boiler to clean out the heat exchanger. Done 3 of these in the past year.
Click to expand...

cOLD OR lIKE WARM ?
cHEERS BUDDY
 
Greenstar Jnr etc with cylinder HEX.

Firing then shutting down going to lock out, crazy CO readings and wouldn't react to gas valve being set up, rubber hose from gas valve had perished and split. Blocked condensate also common if these haven't been serviced, you can usually hear this though, had one recently where the grit that gathers in WB's had totally choked the limestones in the soakaway causing an air lock. Took a bit of sussing out as the condensate wasn't backing up....
 
Remeha advanta plus
When using hot water pretty much straight away even before pre purge the boiler locks out with a e13 fault, hex thermal fuse fault.
If you reset and run heating all will be ok as soon as hw demand e13 fault. I linked out thermal fuse during hw demend and still e13 fault.i checked thermal fuse for continuity all ok, its a known but unusual pcb fault. In my case i removed hw flow sensor so would not activate hw mode and it ran happily for the heating until i returned with pcb 30mins swithed and set up.
 
Ideal logic combi sump. Don't waste your time taking the heat ex out. Rip the old sump off, then use a 42min push pit 90degree elbow on the plate heat ex working it from left to right. Will clip the sump into place.
 
Had a Vaillant ecotec pro 28 yesterday - F75. Checked sensor, was ok but changed anyway, renewed pump head, still no pressure rise detected and still F75. Ended up being a PCB fault 😵

Can be electronic side of sensor, had a few (including new ones) where sensor reads decent pressure, but gauge inside boiler reads zero 😱
 
Attended a 24ri a few days ago with just the blue light flashing - would not fire & was working up until yesterday.
Worcester fault sheet suggested:
Gas pressure
Co2 levels
Electrodes
Gas coils
Possibly pcb.
In other words could be anything.
I picked up a set of electrodes & a gasket.
On removal the rectification electrode was a bit short but the electrodes were sparking.
Removed the fan & found part of the rubber flap in the air-gas mixing chamber was missing. The other bit had passed through the fan & was sitting in the bottom of the burner.
Another merchant visit new flap installed & boiler rebuilt.
Still exactly the same fault.
Both coils tested & good resistance 35v being sent by board so all ok there. Gas pressure 23mb but noticeably no drop when the boiler was trying to fire. I would have expected a good 1 or 2 mb drop when trying to fire so deduced that the gas valve had also failed. Fortunately had a spare in the van which does several of the Worcester range.
Factory reset as a start point & apart from 440ppm it fired.
All adjusted to book Co2 settings.
In all about 5 hours including merchant visit.
So the fault sheet was more or less correct in that all those things were wrong with the exception of the pcb.
A bit unusual to get 3 parts fail at once, fortunately the customer was perched on my shoulder & could see each faulty part as they were uncovered.

Regards

Arthur
 

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