boilermate 2

[valentino46]

If anyone can give me the heads up this problem it would much appciated.
I have a boilermate2 which is eight years old and been hassle free until now,it started a couple of weeks ago when it started making rumbling noises which sounded like an airlock filtering through and then like a resetting noise but everything still worked fine until one night when the radiators started getting damn hot, this is when the radiators are selected as perminatly off as it's summer, iv'e had to turn the boiler off and use the emursion heater as my source of hot water.
I have heard this could be a motorised valve but when decribed to me i could not see anything which looks like it.
Any help is most welcome before i get stung by calling an engineer.

 

[superdupergasman]

You could not see a motorised valve as this system does not use any!

Sounds like possibly a couple of faults.....might have air in the system or a boiler stat fault. then there might be a control problem, Pump control board, room stat, timer??

Not sure if this tank switches on the CH pump if it gets too hot but I doubt it.

Get British Gas out on a fixed price repair. £170 including parts and labour

 

[gas4you]

Sounds like a control board issue to me.

You only have 2 pumps on this model, 1 that circulates the water between the boiler and the thermal store, the other that cuts in via the room stat and control board to circulate the stored water to the rads.

Control boards on these are very common to fault.

 

[valentino46]

Thanks for the response, i've seen a part listed on ebay which is described as ' pump drive pcb for mark 2 cylinder' and says it's for the centreal heating pump, do this sound a possibilty?
If so is it a fairly easy fix?

 

[nickso]

the first thing i would check is if there is any water in the header tank. the ballcocks are prone to sticking. if the tank level is slowly dropping you will get overheating/airlocking noises.

if both pumps work when they are supposed to i would try to back fill it and see how much water it takes as it could be our old friend the cold feed is blocked.


edit: i cannot believe the word b a l l c o c k is censored

 

[valentino46]

the trouble is the rads are working when they are switched off, temp wise and flow seems to be fine.
Since the rads started fireing up the noises stoped

 

[mickyg]

pump driver board often makes a funny noise when its knacked, and it also controls your heating pump, gotta be no.1 suspect, doddle to change

 

[pannierstan]

I would suggest replacing both the PCBs on the boilermate as unless you can catch it doing it they are very hard to identify the culprit.

Both are as problematic and are about £50 each new I think

Stan

 

[nickso]

the trouble is the rads are working when they are switched off, temp wise and flow seems to be fine.
Since the rads started fireing up the noises stoped

is the rad pump running when the rads are heating? i think under certain circumstances the BM2 can heat rads by gravity.

have you checked the header tank?

 

[Billybjo]

I have a BM2 also.
A month or so ago I had similar rumbling noises, then one night in bed a loud bang scared me and the mrs sh**less, the dog jumped up 3 feet. Turned out the header tank was empty and foam had been spewing into the tank from the expansion pipe and blew the plastic cover off the header tank! I previously had the cold feed turned off because the ball cock sticks and caused an overflow. My concern was the reason for the tank empty, then I remember we had a rad turned off in an unused room for years and recently turned it on. It must have been empty and used the header tank water (been off since a system drain some time ago).

Does the resetting sound like a relay? If yes I had one of the PCBs fail with a similar problem. I think it was the pump drive one, my brother reparied it for a few pence. Recently the boiler PCB failed and prevented the Grundfos running. This was at the same time as the rumbling so probably caused the boiler pipe feed to overheat (its on a permanent rayburn).

 

[Billybjo]

forgot to say, we also had the rads coming on even though set off. This turned out to be because the boiler feed pipe was so hot (because of the PCB failure), which is where the pipe thermostat is to detect the system being too hot, and its connected to the pump drive override. Do you have a similar thermostat and what is the dial set to?