Warm Air System with room controller - help needed

[GuyE]

Hello all,

My first post here, so be gentle!

Just bought a house with a gas fired warm air system. The original control system was based on a time switch (the old dial with the movable on/off tabs) at the boiler and a mercury switched thermostat control in the lounge (2 wire variety). The boiler has a rocker switch with 3 positions: timed, off, constant. There's also and isolator switch on the electric supply to the boiler.

I've replaced the room controller with a honeywell CM67 room controller. My thinking was that i could use that to do the timing and thermostat duties. I've switched the boiler switch to 'constant'.

Now the problem: Everything works as it should in terms of temp control etc, BUT the fan (for warm air circulation) stays on constantly i.e. independent of the boiler. Problem with this is (1) it's probably not energy (electricity) efficient to have it running 24 hours and (2) the loft ducted air circuit gets cold as soon as the heating is off with the result that some of the upstairs rooms get cold air pumped to them. There's no thermostat in these rooms so they end going from hot to cold to hot etc.

What i would like is for the fan to be on the same curcuit as the thermostat switch (so it goes on and off with the boiler). Is this a possibility?

Sorry for the long explanations but i guess more info is better than less.

Best regards

Guy

 

[ChrisR]

NO. The wau has to decide when to run the fan, so you either have a (new?) wiring error , or the module which controls it is faulty. You may also have a "summer vent" sw which would turn the fan on, to check.
Model would help.

 

[GuyE]

Thanks Chris,

I'm not at home so I don't have a model (sorry).

It does have a Summer Vent switch. I assumed this was to run the fan (without heating) in the summer?? Should i set this to on?

Thanks again
Guy

PS the system was probably installed circa 1980.

 

[GuyE]

Chris the Boiler is a Balmforth Division BD30

I gues they're no longer in business as there's no trace of them on the net.

Should i have the summer vent switch off or on?

Sorry, i am totally clueless at this.

Regards
Guy

 

[cassis01]

Fan control Unit, Manufacturers Part Number BOS00104. Might be the part you are looking for. GC No 385-159.

Good luck

 

[GuyE]

Thanks both for replies.

I was being dumb. The fan does switch itself off, but only after a few minutes of the boiler going off.

Regards
Guy

 

[ollski]

Thanks both for replies.

I was being dumb. The fan does switch itself off, but only after a few minutes of the boiler going off.

Regards
Guy

The fan is controlled by a fan stat in the boiler....it comes on when the heat exchager has reached a certain temperature so it doesn't blow cool air as the appliance warms up and stays running for a time after the burner shuts off to get rid of the heat in the hx.

 

[jg1234]

I am looking to buy a house that has a Balmforth BD30 warm air boiler, does anyone know what kind of flue it has, is it fan assisted?
Would be grateful for your help
Many thanks
JG