Combi Timer Switch

[Tom]

We have a Worchester 24i combi boiler that is installed in an upstairs room and it has a mechanical dial timer and switch on the front panel. As you can probably imagine it is a complete pain to keep going upstairs to turn the heating on or off in the winter so SWMBO has asked me to install a switch downstairs to control the heating. Our rooms have no thermostats and the radiators have no TRVs so the only control is either heating on or off (apart from varying the water temperature sent to the rads by turning the dial on the front panel). What i would like to do is to install a switch downstairs (ideally not mains a powered one), i would imagine i could disconnect the original switch and run a cable down through the ceiling to the Dinning room or Kitchen where it would be more convenient for us. I have looked in Screwfix and think item 33339 which is a Siemans RWB30E would do the trick. This now gives me a few questions.

1) Would this switch be ok to use for the above application, if not please could someone recommend an alternative? 2) I assume i would need a 3 core cable to run the feed, what type should i use? 3) To complicate things further SWMBO has asked if the switch on the boiler to turn the heating on or off can be left active, i don't think this will be possible.

If anyone has done a similar job and can advise it would be much appreciated.

Thanks, Tom

[John Rumm]

Its seems to me that you have a system with very poor controls. Rather than trying to replicate the exact same thing, you have an opportunity here to make things very much better for no extra effort.

It may well, however it would make far more sense to user a thermostat (preferably a programmable one) in the new location. That way you could save the requirement to keep manually controlling the heating.

With a prog stat it does the job of both timer and stat. You simply tell it what temperatures you require, and at what times of day (so it can vary through the day) and it runs the heating as required to achieve what you asked for.

Something like:

a posh 7 day version.

Most battery operated stats like above will run on two wires. The older electromechanical type often require three wires (live, switched live, and a neutral). So to allow most flexibility it may be wise to use three core and earth cable.

3) To complicate things further SWMBO has asked if the switch on the boiler

Can't see why not. Do you want it to have override control (i.e. it can force the heating on regardless of what the stat is doing) or veto control, i.e. it can turn it off even if the stat is calling for heat?

Incomplete article, but may give you some further pointers:

[geoff]

In message , Tom writes

The RWB30E is, to put it bluntly, a pile of s**te. There are plenty of proper modern programmers available - someone else will, I'm sure, recommend one

5A would be sufficient, the pcb has a (well two) 2A fuse

The manual has, IIRC, details for installing an external programmer, it controls the heating, that's what it does, it's function in life, as they say

[Tom]

> Is a posh 7 day version.

Thanks for your input John. I assume that if i install a Thermostat and run it from the main switch on the boiler, when the current switch is positioned to heating on, the thermostat will override this, for instance i would just turn it down to 6c in order to turn the heating off, would the pump or fan keep running? One other problem, when the heating is switched on it is much much warmer upstairs than downstairs, is it possible to have 2 zones on a combi system? If so how much is it likely to cost to make the changes? Money is tight at the moment and i am not to good a plumbing!

Thanks again.

Tom

[geoff]

There are a dedicated pair of connector pins on the 24i pcb for a room stat, as are there for a programmer

look in the installation manual

[Tom]

thanks Geoff, i do not have the manual as the boiler was in the house when we bought it. I'll see what i can find online.

Tom

[geoff]

In message , Tom writes

The installation manual should have been left with the boiler

Ask Worcester-Bosch for one

I might be able to fax / email a couple of relevant pages - phone me on tuesday (details at

[Tom]

Thanks Geoff, i found the manual online from Worchester-Bosch (Both Tech/Spec and User guide), it says nothing about where to connect a thermostat to. After some thought i think i should get some TRV's installed on the rads upstairs and a thermostat in the living room. Do you have any idea how much a plumber is likely to charge? I would guess to supply and install 3 TRVs and a thermostat i would be looking at around £200, please let me know your thoughts before i start ringing around on Tuesday - i am located on the outskirts of Chester BTW.

Thanks

Tom

[geoff]

In message , Tom writes

No - you want the installation manual, not either of the above

Because they are both the wrong publications for what you require

[John Rumm]

With most combis the boiler controls the pump and the fan as required. So if the timer is on, and the stat is not calling for heat then the bolier, pump and fan will be off. When the stat calls for heat the voiler will fire and bring up the pump and fan as required.

You can have two zones with pretty much any type of boiler including combis. Each zone could be controlled by its own stat and /or programmer.

However it seems like you may be able to fix the problem with a bit of balancing. This is just a process of tweaking the flow through the rads in the hotter rooms to even out the heating such that it is more even.

Thermostatic rad valves in the hot rooms would also be easier to fit than zoning the whole system probably.

[Owain]

People have mentioned programmers, but I don't think anyone's mentioned a *wireless* one which would save you having to run, erm, wires.

Owain