Need to replace heating controls - advice needed

[Johnser]

Hi

Looking for some advice. we have a standard heating controller which has now failed for the second time and we would like to replace it with a newer digital timer with a wireless thermostat we can place in another room.

We have a Immerstat Flash controller which controls the boiler only. I believe the boiler is a closed system and isnt a combi boiler.

The Immerstat flash is located in the hall and is connected (i assume) to a standard RS thermostat which is also located in the hall. The location of the thermo is the reason why we would like a wireless thermostat, so we can place that is another room. We have a three storey house and the hall is always cold du to the volume of air 1 radiator has to heat. The thermostat really is only for use of heating the water in the summer.

I have looked at the wireing of the Immerstat and I'm confused. The instructions of the immerstat state that the wireing is as follows:

1 - Mains Live
2 - Mains Neutral
3 - Device Neutral
4 - Device Mains

Now the confusing part. The Immerstat wireing in my house is as follows:

1 - Brown
2 - 2 Blue wires
3 - No Connections
4 - 2 brown wires

Also the Thermostat has two brown wires going into it. I'm assuming that the thermostat is connected in series to the boiler and this turns the boiler one providing the timer is on and the temp is met?

What im asking is why would the timer the wired that way?

Sorry its so long winded!

Thanks for the help

John

 

[securespark]

Photos would help, but I would say that the two blues in one terminal are both the mains in and device neutrals in one terminal instead of them being in their own terminals.

The two device lives: well, one must go to the immersion element and one to somewhere else: this is where the photos may be helpful!

When you say "boiler", are you talking about the gas or oil or LPG fired device running the CH and HW systems in your house, or are you talking about the copper cylinder with pipes connected to it?

 

[ericmark]

Shown is typical boiler wiring showing typical way in which the timers works.

Colours mean nothing except for tracing one device to another as often blue is used as line so what you post is no real good as to working out what goes where.

Today thermostats can be combined with timers so instead of just switching off it changes the control temperature removing the need for frost stats. There problem with wireless thermostats is although simple on/off are cheap enough the type that change the temperature are very expensive.

The norm is to have the thermostat in the coolest room there really to turn system off in the summer. The TRV (thermostatic radiator valve) is what controls room temperature.

So does the central heating heat the domestic water as well? If so is there a thermostat on the storage tank which switches some valve on/off.

There are what we call Plans and first is to find what plan is being used. I think the plan shown is Y plan there is also a W, S, and C. I have not worked on one for many years today things have moved on.

So please some more information and pictures will likely help.

 

[Johnser]

Thanks for the information. Here are some images.

The wireing to the timer.

Untitled

• Johnser
• 6 Apr 2013
• 1

The cylinder in the hotpress.

Untitled

• Johnser
• 6 Apr 2013
• 1

The boiler is Mynute 16e gas boiler and this does the heating system and the hot water. we have TRV's on some of the rads (main rooms upstairs).

In relation to the wireless thermotstat not looking for anything fancy, but the ability for the heating to have reasonable chance of getting to temp. becuase our hall is always so cold, the thermostat isnt really in use during the winter as the hall wouldnt get to 20 degrees even with the heating on 24hrs. The landing upstairs would be warmer and would give a good representation of overall house temp.

Also in the hotpress there is a Myson MPE222 valve (which is currently broken and locked in the open position - new one about to be delivered).
This valve I believe either heats the radiators or just the hot water.

John