Central heating pump (Grundfos) stays on, no hot water etc

[MadaCup]

Hi all,

My central heating has developed a problem whereby the loud pump (Grundfos Selectric) stays on once the heating/water timer should go off. If I don't turn the pump off at the main or put the speed to 1 (from 3) then it would run 24/7.

I have also noticed that during the timer or if I set the heating or water to come on manually, the radiators do not heat up correctly.

The pump is a Grundfos Selectric (seems to be the same as this: http://www.screwfix.com/p/grundfos-15-60-domestic-circulating-pump/67637)
The heating controls are a honeywell ST6400C which seems to be operating correctly (lights come on, LCD is working etc).

From doing my research it appears the Grundfos pump is most likely to be the culprit, I found a receipt dating back to 2001 so I'm not sure how long they are meant to last.

Does it seem likely that the problem is caused by the pump and how easy would it be for a mid level diy-er to replace this with a like for like example?

Thanks,

Adam

 

[DP]

From doing my research it appears the Grundfos pump is most likely to be the culprit

Sir, I suggest your research is flawed. Is your finding based on 'look-see' only or is it duduction based on pratical fault diagnosis i.e. testing with a multimeter etc.

Do you think it is magic that makes the pump run? What is the function of numbers 1, 2 and 3 on the pump? Why do you think the radiators are not heating up properly when you select speed 1?

 

[biscuit77]

One off your zone valves are sticking on mate.

 

[MadaCup]

From doing my research it appears the Grundfos pump is most likely to be the culprit

Sir, I suggest your research is flawed. Is your finding based on 'look-see' only or is it duduction based on pratical fault diagnosis i.e. testing with a multimeter etc.

Do you think it is magic that makes the pump run? What is the function of numbers 1, 2 and 3 on the pump? Why do you think the radiators are not heating up properly when you select speed 1?

I think you are right, having read up more I'm seeing more references to the pump overrun stat (e.g. here: //www.diynot.com/forums/viewtopic.php?t=162476&start=15). Any suggestions as to what it could be?

I'm presuming I should be contacting a heating engineer rather than a plumber?

 

[MadaCup]

One off your zone valves are sticking on mate.

Ok thanks, I'll have a look in to this.