Switchmaster 400

[Nobag]

Hello all
Sorry if this has been covered elsewhere, but i couldnt find anything.
I have a Baxi Bermuda boiler which is controlled by a switchmaster 400, there are 4 cables going in the controller. one is the live feed, two go to the boiler and the fourth goes to the pump. the hot water is on gravity feed with no control valve. I would like to fit a Honeywell T6360 thermostat to the controller, I have some 5 core cable but am unsure on the connections, any help would be great.

Untitled

• Nobag
• 17 Jan 2011
• 1

 

[ericmark]

Likely goes between No 1 terminal and the cable in the number 1 hole now. However central heating normally follows one of the Honeywell plans and without knowing exactly which plan your system is wired to one can't be 100% sure of connections.

With many plans the thermostat does not directly control the boiler but controls the motorised valve and then a micro switch inside the valve in turn controls the boiler. This means if the valve sticks the boiler will not fire up so reducing the chance of overheating should the valve fail.

With three port three position valve likely the brown (Call) wire on valve. However with two port valves they don't always have the micro switches fitted so there is no single answer to your question.

 

[spraggo]

I have some 5 core cable but am unsure on the connections, any help would be great.

Untitled

• Nobag
• 17 Jan 2011
• 1

The four wires are as follows:

1, L N E mains in = L N E on clock
2, L N E Permenant live to boiler for front fire bulbs = L N E on clock.
3, L N E Switched live to boiler = 3 N E on clock.
4, L N E to pump = 1 N E on clock.

You need to connect thermostat in series with pump (1) with 3 core and earth as the stat requires a neutral .

 

[Nobag]

I have some 5 core cable but am unsure on the connections, any help would be great.

Untitled

• Nobag
• 17 Jan 2011
• 1

The four wires are as follows:

1, L N E mains in = L N E on clock
2, L N E Permenant live to boiler for front fire bulbs = L N E on clock.
3, L N E Switched live to boiler = 3 N E on clock.
4, L N E to pump = 1 N E on clock.

You need to connect thermostat in series with pump (1) with 3 core and earth as the stat requires a neutral .

Thanks Worked a treat.