Thorn Olympus 38/50B only heating to 1 degrees then switchi

[superroadrocket]

The above boiler has been excellent for 25 years.
Recently, the temperature in house started to decline. The recirculation pump has been changed, and a new Honeywell thermstat fitted.
Boiler fires up when the room below 16 degrees, but cuts out when 18 reached
It keeps coming on throughout the day, but never exceed 18 degrees
Anyone any ideas

 

[45yearsagasman]

What temperature is your room stat set at?

 

[petertheplumber12]

Boiler thermostat set at wrong temperature or faulty, room stat set too low or faulty (I know its new one)

 

[superroadrocket]

New Honeywell Room Thermostat set at 25 degrees
(Same problem with old thermostat - comes on below 16 degrees cuts off at 18 degrees)
Boiler setting 5 (top setting)

 

[superroadrocket]

Additional Information:
I closed down the boiler and then went through the To light the boiler procedure
The Pilot light lit immediately
However, according to the instructions, you then turn the boiler thermostat to 5, and the main burner will start.
The Main burner did not start

 

[superroadrocket]

Additional Information:
The boiler has only been coming on every few hours.
When it last came on, it ran for approximately 15 mins then went off.
I turned up the boiler thermostat, and it came on again.
It went off 10 mins later, I then turned up the boiler thermostat again, and it came on.
When it stops, the circulation pump stops as well
It appears that when the boiler reaches temperature, it shuts everything off
It seems as if the room thermostat has no influence on the boiler, yet this was the same with the old thermostat (which is why we changed it) as well as the new one, so it should not be the new thermostat

 

[Agile]

Your system seems to be wired wrongly!

The obvious advice is to call a competent heating engineer to see where its wrong.

When the stat is calling for heat then the pump should run continuously.

Tony

 

[doitall]

Think that should say when the programmer is calling the pump should run continuously Tony.

Not sure whether the pump comes on with the boiler or htg call.