Gledhill Boilermate II advice please....

[savecore]

I have a Boilermate II, fed by Myson 80SI, which are both now 13 years old.
Replaced boiler-pump* (on Boilermate) approx 2 months ago after it became noisy following a drain-down & refill. Also added Fernox MB1 inhibitor.
Everything appeared ok for past 2 months, but 2 days ago hot water became intermittent and now no hot water other than small initial amount when taps turned on. CH appears fine, but boiler is overheating (metered thermostats) and runs for a while before this occurs. Boilermate demand neon stays on until boiler cools and begins supplying again. Header tank on Boilermate is ok - turned supply to header off and drained of a gallon of ch water from downstairs. Level in header tank fell by a gallon.

*With identical Grundfos pump running at highest speed.

Would appreciate any advice from Boilermate gurus - there aren't many of you about! (Gledhill aren't currently answering the phone)

 

[Terrywookfit]

Does the H/W pump run??

It is common for the sensors to fail!!

The pcb can be interrogated to see what they are registering !!

 

[savecore]

Hi - Yes the pump is runnng at it's highest speed.

Which sensors? Boiler or Boilermate? I think the boiler overheat sensor is probably working as it should be - but am open to suggestions. The boiler runs for quite a while then shuts down even though the Boilermate demand neon is still on. Both the "feed" and "return" to the boiler are fingerprint-removingly* hot at the time. *(I know - painful and inaccurate test).

Again - which pcb - boiler or Boilermate?

Thanks for help so far.

 

[gas4you]

Didn't think that boilermate 2 was intelligent, or new enough to interrogate pcb.

You need to check the pump contol pcb and the pump again.

You also need to check the blending valve on the side at the top. These are quite common to stick, not letting you get hot water.

 

[gas_man_gaz]

not had much experience with these (changed a few sensors) but the manufactures are really good if ya can get through to um

 

[gas4you]

Are you not all thinking of the newer boiler mates with the ntc's that keep going down?

This is the ancient rust bucket with the lever on the front that has the peg to put in the hole to set the temp

 

[gas_man_gaz]

hmmm i could be

they wa still really good wen i dint hav a clue wat was wrong

 

[nickso]

if you are going to have a boilermate the BM2 is the one to have.

the hot water problem you have is our old friend the mixer valve. guaranteed the plastic bit inside has disintegrated and closed the valve to cold only. easy to replace. turn off mains water, run hot tap, undo three unions, let remainder of water out into bucket or somesuch and in the best traditions of haynes manuals- refit is reverse of removal.

 

[savecore]

Ok - thanks all - kudos points to Nickso for accuracy and instructions, followed closely by gas4you.

Spent half today trying to get mixer valve off (13 years old - well seized), to have internal plastic bits shed all over floor....
Finally got through to Gledhill sales after 4pm, to get part number (no answer on tech line all day). Really helpful operator appeared to know part numbers for mixer and thermostat off top of his head (is that a good sign?) and despite saying he wasn't technical, was knowledgeable about the system.
Wolseley/Parts Center York not only agreed to price match online site "because it's Xmas", but reopened shop when I got there just after 5pm.
Just fitted new valve and allowed everything to warm up - looking good.
Have backed-off Boilermate thermostat, to see if it may have been the cause of the boiler overheating and may still have to replace it at some point.

Seems to be mixed feelings out there about this system, but this one has worked solidly for 13 years (in a hard water area) with only a couple of pump-drive pcb failures.

Thanks again gurus......

 

[gas4you]

Wait till you have to drain and re-fill it

Thats when the fun will start