Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

Had the same problem on a sabre. There wasn't enough differential across the fan. If you remove one hose from the aps then the boiler worked fine. Cleaned latent hx and replaced fan,all good.
 
Hi, if you look back on old threads I had exactly the same problem, I rang Vokera and they were most unhelpful, no matter what I did I couldn't get the boiler to fire with the case on. All the could tell me was that I had an air flow problem. I gave up in the end and told the landlord to call Vokera out. I will call the tenant later and see if they managed to fix it. The only thing I didn't do was to remove the flue restrictor, if there is one or clean the heat exchanger with a blade. The boiler has aslo run for a couple of years without any problems. Let me know if you get yours going,
Cheers, casaco
 
I'd go with replacing the venturi as previously mentioned as only a tiny build up of debris is needed to give a low differential across the aps (top venturi normally at fault it can also get dirt into shaft which cant be seen and needs a small screwdriver to clean)
 
I polished the inside of the venturi with emery cloth until it looked brand new, including the shaft, it still won't run unless the front case is opened.
 
Try cleaning out the tappings where the rubber tubes connect to the fan or flue.As mentioned use a small screw driver and some compressed air.
 
The front casing isnt squashing the silicone tubes or the tubes are holed? If its had a new aps check that the small (tiny) screws have been used to connect the bracket to the aps otherwise it may have punctured the casing. One other thing you can try is remove the rolling pin shaped cylinder out of the latent heat exchanger (if fitted). Cant think of anything else to try.
 
Came across with same problem, did clean everything out, dismantled flue to check the pass ways. All clean, hoovered out latent hx, fan clean. APS seems to be working correctly as managed to get the boiler firing with the case closed for some time. It used to run with case on until hot, then could not fire up again for a while. Same story - about 3 years old. Still not running. Any of you managed to get it up and running? I shall try to replace venturis if can source quickly ones, also suspecting a fan is not spinning fast enough. There is no sign of wear tho, bearings looking spot on, smooth spin, no noise just doesn't work for no reason.
 
Have replaced a few fans lately having done the venturis first but you can normally tell that the fan sounds weak.
 
I've got exactly the same problem as this with a Vokera compact 29 he.
About 4 years old...
I've been stressing majorly trying to fix it on a callout this morning, eventually put a new APS on it even though the old one seemed fine. NO change.
The boiler fires (mostly) with the case cover off, but just fast flashing green light, fan and no ignition sequence with cover back on.

I was suspecting the fan may be the problem, is there any way to prove this?! cheers
 
I've got exactly the same problem as this with a Vokera compact 29 he.
About 4 years old...
I've been stressing majorly trying to fix it on a callout this morning, eventually put a new APS on it even though the old one seemed fine. NO change.
The boiler fires (mostly) with the case cover off, but just fast flashing green light, fan and no ignition sequence with cover back on.

I was suspecting the fan may be the problem, is there any way to prove this?! cheers
Ask in the close forum and we can help you there
 
  • Like
Reactions: 1 person

Official Sponsors of Plumbers Talk

Similar plumbing topics

We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.