Pump still running on boilermate 2000

Hi there

We have a Boilermate 2000 and a Potterton Suprima boiler. We are having a situation where if we use a lot of water, the hot water pump stays running long after the boiler has stopped coming on (it's just sat on the orange light waiting to be called). We can just hear the boilermate humming louder than normal.

We have had the boilermate looked at by a Gledhill engineer who said the problem was with the boiler and the boiler looked at by an engineer who has changed the thermistor and PCB, but still the problem exists.

Is this something people have come across?

Thanks

Hi, you need to check a few things in order to decide the most logical cause of the issue.

First of all which if any green LEDs are showing on the Boilermate, and what is showing on the red display. If the two bottom LEDs are on then the boiler should be on (bottom LED), and the boiler pump will be running (2nd LED). You would expect to see ON with some dashes on the display under normal conditions.

If the circ. pump is running without the green LED being on their is most likely an issue with the BM pcb, ditto if no ON showing on the display.

If the above is normal perhaps send me a personal message I can ring you to see if I can help, or contact me from my website and I can ring you.

Contact form at bottom of page: https://murraymartin.yolasite.com/ You can also check out the videos they may help your diagnosis.

Regards Murray

Thanks, we've had the heating on today which has stopped it from making the noise, so will take a look next time it does

When it's making this noise, the boiler does sometimes come on, but goes back to the solid orange light very quickly, and the boilermate keeps making the loud humming noise.

We've had 2 PCBs in the boiler in a matter of weeks but still the same problem.

The Gledhill engineer said it was caused by the age of the boiler and the pipe to the pump not getting got enough, both the pipe on the boiler and the pipe into the boilermate were 60 degrees, although the boiler never seems to stay or come on long enough to heat anything

Hmm, sounds like new boiler engineer required. Lack of volume of water circulating through the boiler can cause the issue you are experiencing, however, I would expect the boiler to be cycling at its set temperature. Gledhill manual says boilers should be set at max so that would be above 60 degrees. With the boiler tripping off I would have thought the output would be really hot, especially compared to the inlet. The boiler has an overheat sensor was that changed that could result in the boiler cutting off at low temperature. Other possibilities are faulty thermostat (not the first time a replacement has been a dud), or issue with the flame i.e. low pressure etc.. I guess your engineer wants you to fit a shiny new boiler (-:. I assume, as you did not mention that all was well with the LEDs and display on the Gledhill. Maybe new year, new engineer. Regards Murray

Great thanks, will check the lights the next time we have the issue.  The boiler engineer changed the thermistor and the PCB twice.

Just seems weird that the boiler behaves fine when the heating is on, just not when we've used a lot of water.

Ah sorry just re read your first post again, I missread and thought it said the boiler circulating pump was running all the time. My mistake it was the hot water pump, that is a classic symptom of the main pcb starting to fail. Please review my video and you will see that when the board does fail the classic symptoms are no red display and sometimes all the LEDs on and the hot water pump running all the time. Obviously there is no indicator for the hot water pump, as you say you can hear it humming. I really must read things more carefully!!! If the pcb does finally fail i can provide an exchange service just refer to my website. Apologise to your heating engineer.... Kindest regards Murray

Thanks again for coming back. We have a service contract with Gledhill for the boilermate so will get back in touch with them.

The last Gledhill engineer said I was the boiler that was the issue.

When this problem first occured we got to the point where when we turned the heating on, the boiler came on, for about 20 seconds, and then went off and then sat trying to come on but failing, then lights on the boiler went green, orange, green, orange then straight l green flashing, which is why the boiler engineer changed the boiler PCB, it then worked for a few weeks, albeit with the humming noise. Could the issue with the boilermate corrupt the boiler PCB or is just a coincidence that the heating started to work again with the new PCB? It's been 2 weeks since we had the last boiler PCB installed, and are having the same heating issue again with it not coming on straight away.

The Boilermate turns the boiler off and on like a switch really, the boiler has a constant live to it as well.  If the BM is going faulty they can do strange things like trying to turn the boiler, or anything else for that matter, on and off rapidly, which is not a good thing, obviously.  Periodically, or as soon as you notice and issue I would check the LEDs and readout on the Boilermate to see what it shows, also when it is acting up try pressing the small lower black pushbutton just to the left of the red display to see if it changes the display.  If it does nothing the board is definitely not working correctly.  You can see how the button works on this YouTube video look at about 3 mins. in; click here  Regards Murray

Ok the issue occurred today and I was able to get the cover off.

The boiler when this was taken was off and hadn't been on for a while.

Hi I see in the image that the main pcb display is showing H-err this indicates either a faulty DHW sensor or an issue with the connection to it.  See attached flow chart.   It may will be the sensor itself they do fail due to the heat, this sensor is located on the pipe at the top of the plate heat exchanger.  It is also worth checking the connections for it which are on the connector at the top of the main pcb.  The connections are made by a spring mechanism and can sometimes work loose.  The connections work by inserting a small screw driver in the slot behind where the wire is inserted.   The cable can also fail at the top of the sensor where the heat can make it brittle.




https://i.servimg.com/u/f18/20/30/98/08/sensor11.jpg

Great thanks for that, we're paying for a Gledhill maintenance agreement so will get them out again. Is there any reason why this only seems to occur when we run a lot of hot water?

Running hot water might heat cause the sensor to get a bit hotter perhaps and this exacerbates the issue, I meant to ask if the H-er has appeared because you pressed SW2 or has it just popped up by itself? The sensors by the way have an electronic chip in them so the heat gets to them eventually. Regards Murray

It was showing that when I took the cover off.  Cycling through display shows other numbers like in the picture above, but always shows HEr on that particular display

We've also been having a problem with when were running the shower, the water starts off hot, then after a while, sat 5 minutes goes cold for like 20 seconds, then goes hot again. This repeats depending on the length of the shower...does this fit with the faulty sensor?

Normally you would have to use SW2 to see that error message so I am a bit surprised it popped up by itself. Anyway if it is shows every time you run through the checks then the sensor or wiring is an issue for sure. As that sensor controls the temperature of the hot water it not reading would cause issues with water temperature. This youtube video gives an idea of how the pcb works. https://www.youtube.com/watch?v=OP5-i_vi1Pw

OK gledhill engineer has just left - he's replaced the sensor so we'll see how it goes. He still said the boiler isnt outputting enough heat to maintain the store temperature. Apparently the boiler is only outputting 50 degrees and it should be 70 odd. It's the same temperature leaving the boiler and entering the boilermate so has ruled out it being scaled up.

Similar to the problem I posted in the boilermate 2 section, but our oil boiler is producing water around 75 degrees instead of 80 degrees, the new boilermate thermostat was set to the factory 77 degrees. I've tweaked the boilermate thermostat down enough so it's just enough for the boiler to trigger the thermostat and kick in the delay timer and after a few mins stop the pump. Looks like your boiler has bigger issues though if 50 degrees is the best it can manage.