Gledhill SysteMate III Thermal Store DHW issue

[arran197]

Went to the above today, it's a thermal store cylinder.

The pump ran on DHW demand, but there was a short bit of hot water, then just cold.

The plate on the front felt quite hot, the pump ran and everything was pointing at the plate being the issue.

However, I rang Gledhill technical department, which apparently costs about 60p a min from landlines and the guy on the phone got me check the temperatures on the PCB. Quite cool actually, there's a little display behind the front panel.

Did some checks and he says the thermal store isn't hot enough. The pump fitted below the plate is a normal 15-50. The chap reckons it should be a special pump, that runs on a lower voltage.

Anyone experienced these?

 

[moogwai]

Is the thermal store getting up to temperature? I think there are 2 black buttons on the pcb....press the lower button and it should tell you the temperature ( if its the gledhill im thinking of) if not then look towards how the boiler is firing....check thermisters. Check pump on circs from boiler .

If it is getting upto temperature then run the hot water very slow and see if the temp gets higher.

Every time ive had a prob with one of these its been a fault on the boiler or the pump on the primarys.

Could be a blockage on the plate, or the shunt pump is goosed....so many things to think of with these thermal stores!!!

 

[smtplumbing]

we had one of these a few weeks ago change the plate heat exchanger same thing happened chock with sludge big time

 

[arran197]

That's the one, with the 2 buttons on the pcb. The guy from Gledhill said the thermal store wasn't hot enough and the pump was incorrect, which it was making a buzzing noise. But to me the plate did seem to be the point at where it was failing. If that isn't the issue I'll have to replace the plate.

 

[Dannypipe]

It isn't a standard 15-50 on quite a few Gledhill units. They often use a modulating 15 50 X18. Which is more like the old style 15-60's. (If you've ever split one to repair it??). Or another one, something like C16. I can't remember of the top of my head. Both are silver, and Grundfos specials for the Gledhills.

That aside, I think the system mate might use a standard 15/50 (I repair a lot of Gledhills, but not many system mates).

What sounds like is happening to me is:

The system is running hot as it zaps what heat is in the plate heat exchanger - which has been heated by the warmth traveling down the connections, and just being in the confines of the store. So you get an initial zap of heat (this is normal). Then the stores sensors register a drop in temp' and run the pump. Check the pump is running. If it is, you should get hot water. If it is running and you are not getting hot water. I would isolate and split the pump. Then check for a sheared impellor. Had this about a month back. If the pump isn't spinning, check it's getting voltage from the board, if it isn't then a sensor is prob at fault. If it is and isn't spinning then again, look at replacing the pump.

BTW - manual can be found here:

Boiler servicing | Boiler maintenance | Heating service | Boiler care | Heating maintenance

 

[moogwai]

You aint gonna get hot water from the plate unless the thermal store has been satisfied as the hot water from the store heats the plate.
If the store aint upto temperature that to me suggests the problem is either the boiler or the pump or the sensors on the store.

 

[moogwai]

Have they got heating?

 

[Ermintrude]

Out out out! I hate repairs but love the croppa!

 

[arran197]

Heating working ok. It doesn't look like I'll be going back to this now.

Been to another Gledhill today, unvented though. The stat on it has Honeywell written on the front, but having rung Honeywel, they told me that they don't actually make the stat, they allow an Italian company to use the name. This stat is a special order, from Gledhill and takes 3 days! The stat fitted at the moment only works when I turn it on its side!

 

[Ermintrude]

Gledhills are riddled! Check u got power to primary pump, relays on pcb are poop

 

[arran197]

Primary pump running ok. Secondary is supposedly the issue! Wasn't the 15 50 x 18 as should be fitted. Pcb seed to be working ok. I'm just concerned the plate may also be the issue.

 

[Ermintrude]

Clean plate with dishwasher tablet or cola? Is plate hot oneside and warm on other but hw starts off melting hot then pulses? Has it got a tmv? Like this lovely lady or is it the boiler mate in white box?