Temporary central heating timer

[Gaz]

My boiler/timer has developed a fault whereby the boiler and timer aren't commucating or have lost connection. An engineer came out today and has carried out an emergency bodge repair by simply twisting the wires together so the boiler is permanently on unless turned off at the switch. He came out quickly as a favour but can't complete the job until later next week.

In the meantime I'm wondering if I can put a basic timer between the wires to shut it down at night & restart it before we get up in the morning? A plug in timer is no good as it would supply 240v to the wires, what I need is a timer that simply completes the circuit at alloted times but does not supply power.
Does such a thing exist, if so where can I get one?

[Mixc]

what about a one of these?

https://media.screwfix.com/is/image//ae235?src=ae235/41365_P&$prodImageMedium$

https://www.screwfix.com/p/honeywell-dt90e-digital-room-thermostat-eco/41365

[DarrenHW]

Remove the mains supply from the Boiler.
Fit a plug socket on the end of the supply cable.
Wire another cable into the boiler and fit a plug on the other end.
Plug it into the timer.

[Mixc]

what about a one of these?

https://media.screwfix.com/is/image//ae235?src=ae235/41365_P&$prodImageMedium$

https://www.screwfix.com/p/honeywell-dt90e-digital-room-thermostat-eco/41365
Oops...
this is just a stat but you can get something similar with a timer.

[Gaz]

The wires in question simply carry the signal from the timer/thermostat to the boiler and tell it to fire up, they don't carry the power supply, on that basis a plug in timer is unsuitable as it would put 240v through what is effectively a speaker cable

[DarrenHW]

There is a 240v supply to your boiler. There should be an isolation switch next to the boiler, simply install the timer on the cable coming out of that.

[paulf-2007]

There are timers with volt free contacts you can get from electrical wholesalers.

[Len Co]

Don't know exactly what your prob is but if you know the control unit is faulty they are quite easy to replace I believe, quite often a new 'front' just slots into the back plate. (Honeywell sent me a replacement unit when I complained that mine had broken even though it was out of warranty. ) If it's a more complicated problem please ignore.

[dave2010]

I'd proceed with caution, to avoid making things worse.

Why not try another "engineer"? This one doesn't sound particularly good. **

Re putting a timer on the boiler power, that might mess will all the other timing in the system, though would probably work as a stop gap.

Do you have thermostats? Might be best to leave the boiler as is, and "simply" turn the thermostats down when you don't want the heat - though the pump noise might keep you awake.

I'd be inclined to revisit my sentence ** above.

I have had similar issues recently. Some of the thermostats/timers are indeed on backplates and can be replaced fairly easily. Others - not so easy. We did have one timer fail completely - and things worked a lot better once it was taken out and replaced.

Also, do any of the thermostats or timers have batteries? These might be very long life (to maintain the date and time during power failers), or more standard batteries. We have had problems with batteries failing or not making contact, which mess up the heating. Worth checking them all off, and replacing any batteries which seem at end of life. You may need to check all the room thermostats - though if they are the ones on the radiators they will be mechanical - so comment about batteries not relevant. You might have both sorts!