Boiler lockout.

[RPerrin]

Hi guys.
I had a new boiler installed approximately 18 months ago, but it seems to regularly lockout with code 9F 855. The installers suggested a frozen condensate pipe, however, it happens even on frost free days. Our oil tank was replaced at the same time, so unlikely to be from contamination (imho). The only common factor I can determine is that the weather is extremely windy each time the lockout happens. Whilst the wind persists, it's difficult to reset the fault, often getting to 856, where a power cycle is required. Once the wind dies down, it resets immediately with no problem. The flue has a long extension kit, mainly because it exits a wall close to an opening window. I've tried rotating this in all directions, but the problem persists.

I'm really just looking for opinions that I can take back to the installer. Is it possible that the wind is interfering with the flue operation, or is this a red herring? The boiler is a Worcester Bosch greenstar heatslave ii.

 

[cross thread]

How long is the flue and how many bends

 

[Exedon]

Kick your installer's arse even if it is freezing (which sounds unlikely) they should have installed condensate waste so it won't freeze!
Could well be flue some clear pictures would be useful.
Got to say current Worcester oil combi is not the best.
We have pulled several out at just over 5 years old.

 

[RPerrin]

The condensate pipe definitely not frozen. I've attached a picture of the flue. It's just shy of 2 metres long.

 

[fixitflav]

The condensate pipe definitely not frozen. I've attached a picture of the flue. It's just shy of 2 metres long.View attachment 372429

You could try disconnecting the flue extension, temporarily, to see if the problem goes away. If it does, the flue is the cause.

 

[Exedon]

With the exception of the 45° bend that's a standard length plume kit.
We fit plume kits on virtually every Grant we fit sometimes twice that length with zero problems.
Get installer back to check flue has been correctly assembled.
Would also check MI for distance between flue and opening windows. On Grant's its 1 Mt that looks close!

 

[RPerrin]

The installer has been back today and temporarily disconnected the plume kit at the 45° bend. Not sure what they will do if it "resolves" the issue. Ill let you know.

 

[RPerrin]

Ok, so it's been a week and we've had more windy weather, but no lock out since the plume kit was disconnected. I find it odd that it can't handle a bit of wind, and other people must have encountered this situation. Do you think this points to a fault with the boiler being too sensitive, or just not capable of clearing "bad air" from the flue? What would be the best option to resolve the problem? Thanks guys.

 

[fixitflav]

Ok, so it's been a week and we've had more windy weather, but no lock out since the plume kit was disconnected. I find it odd that it can't handle a bit of wind, and other people must have encountered this situation. Do you think this points to a fault with the boiler being too sensitive, or just not capable of clearing "bad air" from the flue? What would be the best option to resolve the problem? Thanks guys.

I suppose it's down to the installer to sort it, with this extra knowledge. Does he know exactly what in the boiler causes it to cut out from a backdraught? Perhaps it can be adjusted.

 

[RPerrin]

Yeah, I guess. As it appears to be a fairly common boiler, I was hoping someone might have come across it before. I just like to be armed with as much independent information as possible.

 

[Harry Bloomfield]

Ok, so it's been a week and we've had more windy weather, but no lock out since the plume kit was disconnected. I find it odd that it can't handle a bit of wind, and other people must have encountered this situation. Do you think this points to a fault with the boiler being too sensitive, or just not capable of clearing "bad air" from the flue? What would be the best option to resolve the problem? Thanks guys.

I wonder if that 90 degree at the top, might be facing the prevailing wind direction?

 

[RPerrin]

That was my initial thought, however, one of the first tests was to rotate it to various positions over a number of days, with the same result unfortunately.

 

[fixitflav]

That was my initial thought, however, one of the first tests was to rotate it to various positions over a number of days, with the same result unfortunately.

Maybe remove the bend and fit a cowl?

 

[Harry Bloomfield]

That was my initial thought, however, one of the first tests was to rotate it to various positions over a number of days, with the same result unfortunately.

Fit a cowl instead..

 

[RPerrin]

Thanks. I've passed that information to the installer, and he's going to see if there is one available for that kit. They don't exactly fill me with confidence.