Baxi Gravity Boiler Switch Bypass

12 Oct 2009
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United Kingdom
Hi, we have a gravity fed Baxi FS 801 OF which has a dial on the front with Off/1~6 - presumably for very basic heating control.
As the boiler has a thermostat connected (Hive), I'd like to disable this switch so the boiler is totally controlled by the thermo and not the dial. Sure this is a reasonably simple job so would appreciate any info about doing it myself.
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No you can not.
The dial (Thermostat) controls the water temp in the boiler.
The Hive senses the air temperature in the room.
strange - the Hive thing works fine but sometimes the boiler stops when the Hive is telling it to fire (normally when it's been going for a bit).
is this usual behavior for these kind of boilers or maybe a problem with it?
Usual for all boilers I think... my understanding of how they work...

1. Thermostat calls for heat because the room is colder than the set point.
2. Boiler fires up and heats the water in your system up to the temperature set on that dial on the front of the boiler.
3. When the water in the system is up to temp, boiler stops firing, until the water cools down a bit, and then fires again to bring it up to temp.

2+3 repeat as long as there is call for heat, keeping the system up to temperature. If you didn't have the stat on the boiler, think it'd overheat and bad things would happen.
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when you say 'usual for all boilers', does this include combi's?
my last couple of combi boilers fired up til the thermo stopped it.

(this one is the first gravity one i've taken on and will probably get replaced at some point)
AFAIK is should follow those fundamentals.

Remember that on a pumped system the pump will still run and make noise all the time - it's just the burner that cuts out; perhaps the pump has been inside the boiler and it's that you can hear?
Or perhaps a combi/some boilers can modulate down to a point they can burn constantly/slowly?

I'll shut up now - I'm throwing ideas around but don't really know :) Maybe post the names of the boilers you had before if you want one of the pros to offer an explanation.

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