I have a Johnson and Starley Janus 54 - 64 Modair system and British Gas have a 3 star contract to service and maintain it. Sadly they do not seem to have any engineers who understand the system. To date the room thermostat, the airflow sensor, the fan and the fan speed regulator have been replaced by them but the fan speed still does not modulate - that is it doesn't vary it's speed and frequency - it is either off or on and at a constant speed - no where near the max which means the burners are on much more often with a huge increase in my gas bill!

Any suggestions - what is the connectivity between the control components and where does the control panel fit into it?

With many thanks

Phil, January 2009

I agree with that. Have just replaced the speed modulator with the new type, taking all of 1/2 hour to fit. Came next day delivery from www.keeptheheaton.com.

Have used these guys since British Gas did not want to know about warm air units, neither will they attempt to service it

Jon Seed, March 2009

Hi Phil it is Bill again, after leaving you with a long answer I got to think. You have a contract with British Gas If the fan is not operating as it should it forms a safty issue with the system and in such BG should fix it or Pay a J&S trained enginner to do so. If they do not keep their part of the contract then you can get a specialist to do the work and send them the bill (ask your local Citizens advise if you don't believe me)
All this Internet Chat and A BG 3 Star is having a dog and barking yourself

Good Luck

Bill Hartmann, January 2009

This is the resistor or transformer unit, the fan plus in here and there are 6 relays that form a cobination of voltages either from the restor unit (this is two 5 inch long tubes on top of the unit) or the transformer type (much better) which has a larg transformer and the relays on the other end.
What happens is that some relays bur out and yo get dead spots as the voltage climbs, also as the highest speed is when the most current is drawn then this always burns out. If you want any other help then reply bill@kidsathart.co.uk

Bill hartmann, January 2009