Gledhill Boilermate 2 Pump Runs Continuously

[overthetop]

The pump between the boiler and storage tank runs continuously.

The boiler, a Potterton Suprima system boiler, was fitted with a new heat exchanger and a PCB in 2011. At the same time a new ball valve and anti-corrosion fluid was fitted to the expansion/makeup tank on top of the storage tank.

In recent weeks have become aware that the pump runs 24/7.
I know that the boiler requires the pump to run on for a few minutes after boiler shutdown to dissipate residual heat from the cast iron heat exchanger.
The Boilermate 2 also has the ability to do much the same but only to extract the last bit of heat from the boiler on shutdown.
Not sure if one or both conditions are enabled but it would seem at least one of them isn’t eventually switching off the pump when the storage tank temperature thermostat has been satisfied.

Have read a number of posts on the subject, the problem is not uncommon.
I ask if anyone have had a successful, and not too expensive, answer on what is the cause. I am thinking it a faulty Delay Timer PCB on the Boilermate.

Any advice would be appreciated.

thanks
overthetop

 

[petertheplumber12]

You also have motorised valve or two. One of those may be giving the pump the wrong info. Expense or not you need to get it sorted.

 

[overthetop]

One of the features of the Gledhill Boilermate 2 system is that it do not use motorised valves.
It uses 2 pumps - one for boiler to tank, the other for tank to radaitors.

The storage tank and its two heating coils are arranged in reverse of the more conventional HW/CH systems.

Not prefect, but that is how it is.

 

[twgas]

Is the boilermate getting up to its set temperature?

 

[mickyg]

as above make sure the boiler thermostat is set to max and your store thermostat isnt too high. if all thats ok then it will be the delay pcb

 

[overthetop]

Thanks for your comments.


The boiler thermostat is set to maximum as recommended by the Boilermate 2 user instructions. For a short period of time I did try a lower setting as central heating is not required at present but it made no improvement.

The Boilermate 2 does achieve the set temperature.
I recently turned its thermostat down to about half way since central heating is not required at present.
The pump is not the original, as unlike the central heating pump, it has a British Gas sticker on it. It has 3 speeds. It is currently on its highest speed.
I did temporary turn it down to mid speed when I first become aware of a problem as it was keeping me awake at night. But that didn’t help with the continuous running!

I had noticed that the boiler will switch in/out quite frequently if the pump isn’t set to its highest speed. Even at the highest pump speed the boiler’s behaviour isn’t ideal but I guess that a side effect of the pump’s continuous running sending the hot water around and around!

 

[Boilerman2]

Yuo need to use a Digital thermometer to see what the potterton boiler is cutting out at if less than 75'c the Boilermate may not achieve its fixed temperature! - I'm guessing that as thsi fault has occured since the PCB change on the boiler, the fault may well lie there!

 

[Agile]

Is your pump wired back to the boiler ( I expect ) or to the Boilermate?

Is the new PCB the latest one with more fault codes?

Fitting that involved refitting wires at the boiler.

I suspect a nupty may have wrongly connected the pump. You can look at the connections easily by withdrawing the right hand cover protecting the PCB and parts at the right of the boiler.

Tony

 

[overthetop]

The boiler / pump wiring is, as far as I know, as the standard wiring diagram in the Boilermate 2 installation manual.

The new Boilermate 2 PCB hasn’t got any fault code outputs. I have not yet seen the original PCB for comparison.

I am not planning to make any changes to the existing wiring. I will look for incorrect wiring but since it all worked OK until recent times I will initially assume the wiring is correct. If however, the new part don’t fix it I will look further.

I will also check that the Boilermate’s thermostat is functioning correctly.

 

[overthetop]

I re-read the last post.

Reference was made to a PCB. I now realise the post was referring to the boiler's PCB. My post was refferring to one of the two Boilermate 2 PCBs.


Anyway, as far as I know the boiler pump is wired to the Boilermate.
The Boilermate controls everything. At least it should but I will check!

thanks

 

[overthetop]

To all those who contributed.

I had a successful result.

A new delay timer PCB fixed the problem of boiler pump running continuously and a high boiler modulation.

thanks,

overthetop

 

[shukerr]

Thanks to everyone who contributes to these forums. It has helped me solve my problem with the hot water pump running continuously.

I moved into my house a few months ago and the pump running constantly has been driving me bananas as the airing cupboard and boilermate are just outside our bedroom.

As per the manual I bought a new delay timer PCB and it did not fix the problem!

I discovered that when the store thermostat was off there was still 9v present between neutral (Terminal 3 on the pcb) and the switched live (terminal 2) coming from the thermostat.

I disconnected the thermostat, but the 9v was still present.
I disconnected terminal 2 from the delay timer pcb and confirmed that the pump would switch off after a couple of minutes. The 9v was the problem and so I started looking at the main terminal block.

After reading the manual in some depth I discovered that my Baxi Solo 2 boiler must not be supplied a permanent live which is was being fed from terminal 4 of the main terminal block. Moving this to the switched live on Terminal 7 has resolved the problem and everything is working correctly.

Bit annoying to purchase a delay timer pcb unnecessarily, but at least the problem is resolved. I would suggest that people just check there is no voltage present between pins 2 and 3 on the delay timer pcb (when the store thermostat is off) before buying a new board.

 

[Mugglewig]

Just moved into house with Boilermate 2000 and the boiler to store pump was running continuously. Tried every forum but could not find answer until I found that a frost stat was fitted in the garage next to the boiler and it was wired to feed power to the pump. Took the cover off and found it was set to maximum (Over 20 degrees)! Adjusted to 5 degrees - sorted. hope this simple solution helps someone somewhere.