Bristol 411 heater controls

[irienz]

The mystery of Bristol heater controls .... These never seemed to work as I assumed the controls indicated.

In the course of restoring my 411, parts of the heating system were refurbished and the opportunity was taken to figure out what the controls actually did. The following is the note which I was given:

Direction Switch:

Off Foot area temp controlled
Demist Windscreen cold, foot area temp controlled
Defrost Windscreen temp controlled

Temp Switch:

Off Foot area closed, hot air closed
Cold to Hot Foot area open, temp in transition

From this I understand the main controls work like this: To demist the windscreen, select Defrost and Hot. To heat the footwell only, turn to Off and Hot. To heat the footwell and direct cold air to the windscreen, turn to Demist and Hot. To get cold air in footwell, turn to Defrost and Cold. To turn all off, turn both to Off. This seemed to be consistent with what I experienced in the past but I confess not to having tested it comprehensively since getting the note.

I would be interested to know what others have found.

Chris Browne
Auckland, New Zealand
irie@orcon.net.nz
Cellular: +64-21-617007