Pump Won’t Stop Running

[TD68]

I have an Ideal Classic FF230-280 Boiler on a ‘closed’ system. For some unknown reason the main circulating pump now never shuts off, even if the hot water and central heating are not called for on the timer. The only way to turn it off is to actually turn the main switch off on the wall. I have had a competent plumber look at it and he is stumped, I had an electrician out today and he checked all the wiring of the pump and 2-way valves and he confirms all is in order? Help!

 

[ShaunCorbs]

trace the wiring back your getting power from something easy for a spark or heating engy to sort

 

[TD68]

Many thanks, I do trust the plumber who I have had and the electrician who came today spent a long time testing circuits and came recommended. Any idea where the fault could be - could it be the pump itself? Cheers
Tony

 

[Murdoch]

Many thanks, I do trust the plumber who I have had and the electrician who came today spent a long time testing circuits and came recommended. Any idea where the fault could be - could it be the pump itself? Cheers
Tony

I hope the spark didn’t charge you for a days work.

The fault almost certainly is contained within the boiler controls .....

I’m a spark !

 

[TD68]

Fair play to electricians, he didn’t charge me anything as he said he could not find a fault. Thanks for the tip.
Tony

 

[ShaunCorbs]

Many thanks, I do trust the plumber who I have had and the electrician who came today spent a long time testing circuits and came recommended. Any idea where the fault could be - could it be the pump itself? Cheers
Tony

time for them two to retire or change professions i think

 

[John.g]

I have an Ideal Classic FF230-280 Boiler on a ‘closed’ system. For some unknown reason the main circulating pump now never shuts off, even if the hot water and central heating are not called for on the timer. The only way to turn it off is to actually turn the main switch off on the wall. I have had a competent plumber look at it and he is stumped, I had an electrician out today and he checked all the wiring of the pump and 2-way valves and he confirms all is in order? Help!

Had that happen in relations oil fired system, turned out to be that the auxiliary (end) switch on one of the two port zone valves (Honeywell V4043H) wasn't opening when valve was directed closed, just replaced valve head and all was well, as far as I can remember the grey wire was permanently live to the switch and the orange wire gave the run signal to the boiler.
Your plumber/electrician has probably checked all this out anyway but worth mentioning maybe.

 

[Aire]

Many thanks, I do trust the plumber who I have had and the electrician who came today spent a long time testing circuits and came recommended. Any idea where the fault could be - could it be the pump itself? Cheers
Tony

There's only a couple reasons that this could be happening. And the pump itself isn't one of them. If you've had a electrician test the circuits and he couldn't find anything then he doesn't know what he's doing. The fault can be found in an hour.

 

[TD68]

Many thanks for the replies, I will get the wiring checked again.

 

[Ziggie]

The pump is controlled by a micro switch on the zone valve. one reason is that the micro switch is stuck in the on position. easy to check if there is voltage on the orange wire .from either one of the valves.
Or less likely, that current is being sent from the thermostat wirings to one of the valves.(e.g. One thermostat has been connected to the wrong terminal and is supplying current from the no heating required.

 

[Ziggie]

Another option:

The boiler is controlled by the valves. The pump normally is controlled by the boiler.

There are three connections

Live - for internal use of the boiler ( always live)
SL - made live by valves and switches on boiler
PL - boiler controller switches on pump.

Most boilers continue to run the pump after switching off to allow the water to cool. Mine runs for about 5 minutes.

So problem could be wrongly wired boiler or bad boiler controller.

 

[oz-plumber]

Maybe the pump was wired to be on continuously so as not to switch off when the boiler switches of, causing boiler over heat issues.

May need a 'run on timer' installed so the pump runs for 5 or 10 minutes after the call for heat has stopped

 

[Ben-gee]

Pump could just be wired into a permanent live rather than a switched one, as above many possibilities- should be easy for a competent guy/girl to pinpoint fairly quickly with a multimeter (and more importantly the ability to use it!)

 

[firemant]

I have seen this question before, probably on a different site, so I will give the same answer, albeit a question.

The pump is working! How can the pump be at fault? If all was working okay before and no one was m siding about with it, then my house is on a stuck MV microswitch. Should be a doddle to sort this, TBH. Is the pump getting 230/240v?

 

[Ziggie]

I checked the install manual . The pump is controlled from the combi boiler and therefore there is only one valve connected.

There is an additional question as well as the useful one mentioned by firemant.

Is the boiler running as well as the pump ?

It should be if the MV microswitch is stuck.

If only the pump is running , then it is the wiring within the boiler that needs checking by a GSP.

 

[Harvest Fields]

I checked the install manual . The pump is controlled from the combi boiler and therefore there is only one valve connected.

There is an additional question as well as the useful one mentioned by firemant.

Is the boiler running as well as the pump ?

It should be if the MV microswitch is stuck.

If only the pump is running , then it is the wiring within the boiler that needs checking by a GSP.

You do not have a combi boiler.

 

[Ziggie]

Oops I googled the model must be old age that I didn't fully read the model number.

Thanks Harvest Fields for correcting