Glo-worm Ultracom 38cxi - Keeps on firing up....

[mickyg]

Doesn't make sense to me. Why don't you call glowworm as its under warranty? what does your installer make of it?
You could try range rating D0 on the boiler to about 20 and see what happens, but with 16 rads I wouldn't think this would be your problem.

 

[Agile]

You have to check what d40 and d41 are showing when the boiler is firing on CH !

To get 50 and 52 means the burner must be off.

The way I interpret the instructions, as you seem to have a combi then the boiler should be set to accept modulation from tour controller.

I would agree that you should set d0 to about 20 or lower and see what effect that has. Thats easy to adjust and can always be set higher later for example if the weather gets very cold.

Do you know the heat output of your rads?

Are they normally all turned on?

Do all/most of them have TRVs?

Tony

 

[shaunos]

Ok,

D40 is 70 (same temp it's set to)

D41 is 59


What does this D0 thing do?? It's currently set to 30.

All rads have TRV's, and yes all rads are on.

 

[Agile]

A differential of just 11° C implies to me that there is plenty of flow.

I would still recommend you set the d0 to about 18 kW though and see what effect that has.

Tony

 

[shaunos]

What does the D0 setting alter???

 

[Agile]

This is the setting in kW of the maximum output power of the boiler when on full modulation.

Owners seem to find that confusing because they think the knob on the front of the boiler does the same thing. Thats wrong of course because the boiler knob sets the maximum temperature of the flow.

If a working boiler shuts down too soon thats often because the power output is set too high for the load if the flow rate is correct.

The boiler then enters its anticycle mode for several minutes but during this time does not deliver any power to the load.

The requirement is to set the maximum power which keeps the boiler on for most of the time. However, this setting will vary if the load varies.

Tony