CH timer workaround - is it safe?

[anon]

My central heating timer is one of the old mechanical types where a disc slowly rotates with time, and the central heating is switched on and off by plastic knobs attached to the disc.

The problem is that it's very old and the plastic knobs just get pushed around the dial so the heating wither stays on, or stays off depending on which knob actually managed to switch it last.

The timer is plugged into a wall socket. Would it be OK to buy a timer plug from Argos, set the times on that, and plug the broken timer into it? that way I could leave the old mechanical timer to "always on" and use the digital plug-in timer to control the heating by switching the power to the old timer on and off.

Are there any safety issues with this?

I am assuming that my boiler has a seperate power supply to the timer. Is this always the case?

[Andy Hall]

Probably not unless the thing falls apart..

However, it is a simple and inexpensive job to put in a nice new proper timer so that would be a far better option.

It really depends on how the system is wired. If the timer is plugged into a wall socket then the boiler should be getting its supply from that as well, otherwise the setup isn't safe anyway.....

It would be a good idea whatever you do, to look at and sketch out how everything is wired. If you need help with that, post back again.

.andy

To email, substitute .nospam with .gl

[geoff]

In message , anon writes

I presume you are talking about a Randall 102 or 103

Better to buy the electronic equivalent e.g. Randall 105E, no need to rewire anything and it

[IMM]

Too true Maxie, also the ubiquitous Landis & Gyr mechanical version has a direct replacement digital model.

[geoff]

For those of us with a bit of relevant experience,

"The problem is that it's very old and the plastic knobs just get > >pushed around the dial so the heating wither stays on, or stays off > >depending on which knob actually managed to switch it last."

gives it away as being a 102 or a 103. The direct backplate compatible replacement is the 103E or the 105E

To replace it with any other make would involve replacing the backplate and rewiring it

listen and learn

[Steve]

We had an old Randall with the same symptoms, and bought a Drayton Tempus Seven from B&Q, for about 40 quid. It comes with a replacement backplate and a simple wiring diagram, and was pretty easy to fit. It works a treat.

[geoff]

In message , Steve writes

A 105E will do the same without a rewire

[SantaUK]

Their not getting it are they! Yup, I had the 103 and direct replacement with the 105E - what a difference - changed and programmed in two minutes :-))

[geoff]

In message , SantaUK writes

One can only try