Pressure loss on Worcester 12 / 14 Heatslave oil boiler

[Burnerman]

I'm going to look at one of these tomorrow, courtesy of brother in law.
Its installed in his holiday cottage so we don't know how long it took for the pressure to drop, but its been working well for years.
He reckoned that the boiler was completely down on pressure, and this morning the burner had locked out. He repressurised it, pressed the lock out button and it came back to life.
Just a couple of queries to get me thinking:
Does pressure drop cause the burner to lock out, or is that a coincidence?
There are no visible leaks; PRV is new so is there likely to be a problem with the DHW heat exchanger? The boiler age is unknown.
The cottage is 50 miles away so I'd like to be prepared!
Thanks for reading, and have a good evening, all.
Cheers John

 

[Boilerman2]

pressure probably was low, but went right down when the burner locked out and the primary store went cold Check the expansion vessel for the correct air charge, remember to have a drain open whilst you pump up the vessel, the water pressure will have played no part in the burner locking out assuming it was not overheat lock out?
check that the PRV is not dripping and another hot spot on the heatslave is the AAV on top of the heatstore (its a pig to get at - typical worcester!!)

Burner may just need a good service but Solenoid Coils and EBI Ignition transformers are prime suspects on the B9 burner!

Good luck - at least its not a Rayburn this time!!

 

[cider]

Perhaps he pushed the over heat reset, not the burner re set as they are no linked.
Low pressure will always trigger oh stat.
As for heat ex causing low pressure, not possible as it would increase boiler pressure not lower it.
He probably has a small leak somewhere which has caused the system pressure to drop.
Pump valves seem to leak (ball type).
Also take a universal aav as they can leak and the water evaporate leaving little sign.
I no one knows the history of mainternance and your BIL has had the cottage sometime presume sweet f a has been done.
Personally I would try and get someone local to do maintenance on the boiler cus you know with family it will go t i t s up.

 

[Burnerman]

pressure probably was low, but went right down when the burner locked out and the primary store went cold Check the expansion vessel for the correct air charge, remember to have a drain open whilst you pump up the vessel, the water pressure will have played no part in the burner locking out assuming it was not overheat lock out?
check that the PRV is not dripping and another hot spot on the heatslave is the AAV on top of the heatstore (its a pig to get at - typical worcester!!)

Burner may just need a good service but Solenoid Coils and EBI Ignition transformers are prime suspects on the B9 burner!

Good luck - at least its not a Rayburn this time!!

Hi BM2
Thanks for the reply..... I put a new EV on last summer as the old one was leaking around the seams, together with a new PRV. (10 psi on the EV). I noticed when I had the top of the boiler off there was evidence of leakage around the AAV but it wasn't recent so I let it be. Apparently brother in law was faffing around with the radiator TRV's before the lock out occurred so you may well be on to something regarding overheat lock out.....I'll pop up there to see whats what in a day or so. At least my gas analyser is working now So, do you not expect a DHW heat exchanger then, if no leaks are found? Many thanks again for your time John

 

[Burnerman]

Perhaps he pushed the over heat reset, not the burner re set as they are no linked.
Low pressure will always trigger oh stat.
As for heat ex causing low pressure, not possible as it would increase boiler pressure not lower it.
He probably has a small leak somewhere which has caused the system pressure to drop.
Pump valves seem to leak (ball type).
Also take a universal aav as they can leak and the water evaporate leaving little sign.
I no one knows the history of mainternance and your BIL has had the cottage sometime presume sweet f a has been done.
Personally I would try and get someone local to do maintenance on the boiler cus you know with family it will go t i t s up.

Many thanks for that, cider - I was thinking along similar lines as the mains pressure is considerably higher that the 1 bar boiler pressure so the CH water couldn't pass into the DHW.
I'll have to check again for leaks - but everything is buried under a bliddy laminate floor so it makes things difficult.
I wasn't aware that low pressure will trip the O.H stat every time so thats now in the brain cell.
So, its boiler top off again to check the AAV....away goes the tumble drier thats balanced on top of a work top thats tiled in - boiler beneath.
If the pope fancies creating another saint I think I'd be a strong candidate!
Best wishes and thanks again John

 

[Burnerman]

Just an update on this one....
Arrived to find water dripping from PRV overflow and boiler pressure 3.5 bar. BIL hadn't turned the filling loop off fully.
Pump pressure was 145, where MI's stated 100 psi.
Lifted top off the boiler, AAV leaking smugly. It does look a right sod to fit too - maybe with the front panel off it will be easier.
Many thanks to Boilerman2, cider and kev for the invaluable help!
I'll be back up there on Friday.
Cheers John

 

[kevplumb]

check your e mail john

 

[Burnerman]

check your e mail john

Just have done mate - many thanks again

 

[greenrayburn]

We have a Rayburn 499kb(1997). the boiler leaked on it and we were yold by Aga that was the end for it as the boiler and oven are connected. We have disconected all the water pipesand elctrics to the boiler side. But now when the cooker gets upi to temp it cuts out and will not re strart. Is this dangerous? How can we keep using the cooker? any ideas greatley welcomed

 

[Burnerman]

Ye gods mate I thought I was unique in working on one of these....Has your Rayburn a Nu Way burner or one of the Eco-Flam ones?
The boiler side burner heats up a cast iron heat exchanger, the cooker side simply draughts its hot gases around the oven area, and the gases meet at the combined flue, back right of the Rayburn.
Notice on the control panel, under the hinged cover, top left, where the programmer is. You'll see 2 reset buttons, one marked cooker and the other marked boiler. The cooker is the top one. Has the pip pushed out a bit? If it has, push it back in with a pencil or similar. This will reset the cooker overheat.
The overheat thermostat phials are grouped together, behind the panel that houses the programmer. There are 3 of them, pushed into a steel tube. There might be some insulation in the way, but you'll see them, and they connect to the controlling thermostats on the same panel as the programmer.
So, are you simply using the Rayburn as a cooker? I'm not to sure how successful this will be, as the CH water keeps the boiler unit from overheating due to the water dispersing heat.
John

 

[cider]

How can we keep using the cooker?

As a door stop

Its overheating because the boiler isnt removing the extra or latent heat.

 

[greenrayburn]

How can we keep using the cooker?

As a door stop

Its overheating because the boiler isnt removing the extra or latent heat.

Are we wasting our time. Is there no way we can just use it as a cooker or is it very dangerous to do as Rayburn have told us. Jane

 

[Burnerman]

I'm going to stick my neck right out here.....so, the water heating system has been drained and disconnected from the Rayburn, correct? Therefore the boiler pipe outlets must not be capped, so any residual water can steam away. The cookerside burner is the one on the right (please correct me), and its gases go around the cast oven box and then up the flue.
I can't see any reason why you can't go ahead really, but in a normal installation - if Rayburns are ever normal - the circulating hot water takes heat away from the firebox area which may get hotter than normal - although the cooker burner is well out of the way from the main boiler. There may be a chance that the unit will shut down from time to time due to overheating and there is a 'reset' button on the panel which has to be pushed in manually should this happen.
So, to recap - all you are doing is heating up a huge lump of metal, that has no water inside but its boiler is open to the atmosphere so that expansion can take place. This is the important bit! You can't expect Rayburn to endorse what you are considering as they can't be responsible for any consequences. John

 

[greenrayburn]

Hi, yes all has been disconnected and nothing is capped. The cooker will fire up but once it reaches temp it cuts out and will not start up again until the cooker is nearly cold. You can not push the red restart button in also until is nearly cold. Jane

 

[kevplumb]

just a thought (and that's all it is )

we used to fill the old s/f bbs with sand

dunno if it would make any difference