Downstairs radiators intermittently not heating up

[Harry Bloomfield]

Get two short pieces of insulated cable, and two insulated connector blocks,turn mains power off. Release the live and neutral conductors from the pump, put them into separate connectors and add the short lengths into the pump. You can then test on the connector blocks terminals.

One of those occasions, where a test lamp is invaluable. Just a lamp holder, with a bit of twin flex connected to it, plus some sort of lamp - the smaller, and the lower powered, the better. I've been known, to whip the plug off a table lamp, and use that as a test lamp.

 

[ro63rto]

Get two short pieces of insulated cable, and two insulated connector blocks,turn mains power off. Release the live and neutral conductors from the pump, put them into separate connectors and add the short lengths into the pump. You can then test on the connector blocks terminals.

I was thinking about that, got some wago blocks somewhere. Was just wary of the plastic spring clips that hold the conductors in place. The pump is at least 20 years old if not more and plastic doesn't fair well in that hot environment. I'll give it a go tomorrow. Thanks.

 

[terryplumb]

If you use wago connectors , will your meters probes fit ? Connector blocks wouldn't have that problem.

 

[ro63rto]

If you use wago connectors , will your meters probes fit ? Connector blocks wouldn't have that problem.

Good question. Ne er tried. Better dig out the chocblocks.

 

[ro63rto]

Got a call from mum this morning.
The heating is back on downstairs. She thinks the house is haunted because the right hand slots on the 4 slice toaster also started working this morning.
At this point I don't even know what to check. Could a pump not work for s week then spring into life or even the room stat for that matter ?

 

[JohnD]

.

 

[terryplumb]

As the room thermostat is firing up the boiler you can pretty much rule that out.
It sounds like there could be a loose connection on the wiring. It's unlikely that the pump itself is intermittently faulty ,when they fail,they don't usually recover .
To reiterate ,when it doesn't work that's when you check voltage.
The toaster isn't related !

 

[ro63rto]

As the room thermostat is firing up the boiler you can pretty much rule that out.
It sounds like there could be a loose connection on the wiring. It's unlikely that the pump itself is intermittently faulty ,when they fail,they don't usually recover .
To reiterate ,when it doesn't work that's when you check voltage.
The toaster isn't related !

Thank you. I'll hold off on swapping the room stat for now.
This weekend I'll go round and set up the connector block/wiring as you suggested and take some readings if it fails again.

 

[Harry Bloomfield]

Wire a test lamp, as I described above, across the pump/in parallel. A test lamp, makes it very obvious, when the pump is powered. When lit, the pump obviously has power, then you just need to check whether the pump is running, whenever the lamp is lit. Simple!

 

[ro63rto]

Wire a test lamp, as I described above, across the pump/in parallel. A test lamp, makes it very obvious, when the pump is powered. When lit, the pump obviously has power, then you just need to check whether the pump is running, whenever the lamp is lit. Simple!

Not sure I have a spare 230v lamp. I'll check mum's garage and see what they have.

 

[ro63rto]

Right. Small update. Pump was unwired from the boiler and a 3pin plug put on and plugged in. Pump instantly and silently started to whirr. Heat was back in the downstairs rads. The plumbers that came had no idea on the boiler even with the wiring diagram on the case so they rang the manufacturer, Ideal. Turns out my Scrooge dad replaced the faulty boiler (25 years ago ish ) with one from 1978 and no one at Ideal are old enough to remember this model.
I'm going to put a timer on the socket that the pump is now plugged in to so it turns on and off with the controller then in the spring we'll probably have to stump up for a new combi boiler. Unfortunately none of the government grants I've seen can be used on a combi but only air source or biomass so we'll be looking at a minimum of £4k.
Thanks to all that helped.

 

[JohnD]

I'm going to put a timer on the socket that the pump is now plugged in to so it turns on and off with the controller

Surely it could be wired to turn on when the boiler does.

 

[ro63rto]

Surely it could be wired to turn on when the boiler does.

That's the point, it was working for 25 years or so but no longer does. No power at the pump or room stat so in the meantime, until I find the fault, it will be plugged in to mains socket on a timer.