Replacing old boiler control

[andderson365]

Hi,

Moved into a new house with original 1982 boiler, which we are hoping will last us a few years until we have the money to replace since we were 2k above the boiler replacement schemes income threshold.

The boiler is controlled by a antique looking wall unit resembling a light timer. Is it possible to replace this with something similar to this?

http://www.toolstation.com/shop/p58054

At the moment water has to be on when central heating is switched on, is this a consequence of the old style system that I have installed?

 

[jackthom]

Sounds like an old gravity hot water system. So whenever the boiler is firing there will be some heat going to the hot water cylinder.

I'm guessing there are no motorised valves involved so presumably just boiler, pump, room thermostat, cylinder thermostat and the programmer/timer.

Can you post some photos of the programmer and the wiring on the back of it?

 

[andderson365]

Hi Jackthom,

I think its an old gravity system we have. The boiler is an antique but still going strong. I have added the requested pictures, hope this helps.

Untitled

• andderson365
• 22 Nov 2014
• 1

Untitled

• andderson365
• 22 Nov 2014
• 1

Untitled

• andderson365
• 22 Nov 2014
• 1

Untitled

• andderson365
• 22 Nov 2014
• 1

 

[Wongfeifox]

If it is a gravity system there will be no cylinder thermostat, the hot water is controlled by the boiler thermostat, another way to tell is if the flow and return pipes to the cylinder are in 28mm, that's a dead giveaway. The pump will only come on when the central heating is on with a demand is another easy way for a novice to recognise gravity hot water systems. Check for all this stuff before making that conclusion, could just be poor wiring.
The requested thermostat (what is it with people and salus ? Spend some money and at least fit a Honeywell wireless stat, you'll thank me in the long run when your swearing at your salus for the thousandth time) is only a single Chanel, ie it will only control the heating which means it is better suited for a combi. It could be fitted to this system but you need to either leave the original clock in place to control hot water or fit another modern controller to do the same job.

Find someone who does a dual Channel controller, or better yet wait until you replace the boiler and upgrade the entire system because if aesthetics is all your worried about then that old Baxi is an eyesore and costing you a fortune to run, so save the money and put it in the piggy bank

 

[jackthom]

I can't quite read the model number of the programmer but it looks like a Landis & Gyr RWB2.

If you look at the questions/answers for this Siemens unit...

http://www.heatingcontrolsonline.co.uk/siemens-landis-staefa-rwb29-programmer-p-43.html

it should be a direct replacement and fit on the existing backplate.

 

[andderson365]

Thanks for the information, the control I posted was the first I encountered.

I will look for a 2 channel, thanks for the advice on that. Regarding swapping them over:
Is it relatively straight forward using the same wiring?

 

[jackthom]

It's straightforward to rewire it with any programmer if you can identify the function of each of the wires connected to the old timer.

If you replace it with one which can plug into the old backplate there's no need for any rewiring.

 

[andderson365]

Thanks for all the info jackthom, sounds like a job for my Christmas break[/list]

 

[slapper]

Don't get any Salus gear its rubbish, Get yerself a Horstmann Tiara programmer. Ideal for your situation