Combi boiler radiators not heating up

Myci85

I'm sure you've checked, but I know I sometimes have brain freeze with heating systems when not used for a long time. Have you checked the room thermostat is high enough that heating should come on (its obv warmer still than some have it set to come on in winter)? And that the heating isn't on some sort of timer mode meaning it only heats radiators at certain times of day? Only other thing I can think of is on our last combi boiler, if the batteries had gone in our room thermostat, the heating wouldn't come on. 

Eldi_Dos

Ayr_Rage said:

WIAWSNB said:

How long did you leave it calling for heat? That does look like the 'syphon fill' symbol, and it looks as tho' the DHW doesn't do this, so it needs the CH to be running for a while - which it does at a slow rate until the trap is filled.
Try leaving it for longer - give it a good half hour. 
https://www.worcester-bosch.co.uk/support/troubleshooting/faqs/all-faqs/what-do-the-error-symbols-mean-on-my-boiler
If it still doesn't work, call WB up on that number - it is surely still under warranty? 

@topcat105's boiler only runs for 30 seconds in heating mode before shutting down so no chance to fill the syphon.

It needs an engineer!

If you read the link WIAWSNB posted you will see WB describe the boiler going into "low burn" mode while it goes through its function to fill the trap. Low burn mode suggests to me that you would not hear boiler function at this stage.
Following WB,s instruction and carrying out the sensible checks mentioned by Myci85 are the way to go at the moment, before going to the expense and inconvenience of calling out a engineer, who I would wager are inundated with calls about problems like this just now.

Albermarle

Eldi_Dos said:

Ayr_Rage said:

WIAWSNB said:

How long did you leave it calling for heat? That does look like the 'syphon fill' symbol, and it looks as tho' the DHW doesn't do this, so it needs the CH to be running for a while - which it does at a slow rate until the trap is filled.
Try leaving it for longer - give it a good half hour. 
https://www.worcester-bosch.co.uk/support/troubleshooting/faqs/all-faqs/what-do-the-error-symbols-mean-on-my-boiler
If it still doesn't work, call WB up on that number - it is surely still under warranty? 

@topcat105's boiler only runs for 30 seconds in heating mode before shutting down so no chance to fill the syphon.

It needs an engineer!

If you read the link WIAWSNB posted you will see WB describe the boiler going into "low burn" mode while it goes through its function to fill the trap. Low burn mode suggests to me that you would not hear boiler function at this stage.
Following WB,s instruction and carrying out the sensible checks mentioned by Myci85 are the way to go at the moment, before going to the expense and inconvenience of calling out a engineer, who I would wager are inundated with calls about problems like this just now.

The boiler is only 3 years old, so presumably is still under warranty, assuming the OP has had it serviced annually of course.....

WIAWSNB

Eldi_Dos said:

If you read the link WIAWSNB posted you will see WB describe the boiler going into "low burn" mode while it goes through its function to fill the trap. Low burn mode suggests to me that you would not hear boiler function at this stage.
Following WB,s instruction and carrying out the sensible checks mentioned by Myci85 are the way to go at the moment, before going to the expense and inconvenience of calling out a engineer, who I would wager are inundated with calls about problems like this just now.

Good point - if it 'shuts down' with that symbol displayed, it does suggest it's still trying to fill the trap. Ie, it hasn't actually 'shut down'.
Topcat - what exactly takes place? You say it 'shuts down' - what do you mean? And, more importantly, what do you then do - turn it off, or leave it?!
If the former, then try the latter

born_again

3 year old. Has it been serviced? 
Now is a good time to get it serviced. 

Eldi_Dos

Albermarle said:

Eldi_Dos said:

Ayr_Rage said:

WIAWSNB said:

How long did you leave it calling for heat? That does look like the 'syphon fill' symbol, and it looks as tho' the DHW doesn't do this, so it needs the CH to be running for a while - which it does at a slow rate until the trap is filled.
Try leaving it for longer - give it a good half hour. 
https://www.worcester-bosch.co.uk/support/troubleshooting/faqs/all-faqs/what-do-the-error-symbols-mean-on-my-boiler
If it still doesn't work, call WB up on that number - it is surely still under warranty? 

@topcat105's boiler only runs for 30 seconds in heating mode before shutting down so no chance to fill the syphon.

It needs an engineer!

If you read the link WIAWSNB posted you will see WB describe the boiler going into "low burn" mode while it goes through its function to fill the trap. Low burn mode suggests to me that you would not hear boiler function at this stage.
Following WB,s instruction and carrying out the sensible checks mentioned by Myci85 are the way to go at the moment, before going to the expense and inconvenience of calling out a engineer, who I would wager are inundated with calls about problems like this just now.

The boiler is only 3 years old, so presumably is still under warranty, assuming the OP has had it serviced annually of course.....

If you follow the link posted WB they give a number to call to talk you through problem.To arbitrary just call a engineer out when a fault may not actually exist could result in a call out charge,never mind the inconvenience and possible loss of income if you have to take time off work to attend.
So I would say best be sure there is a fault before going down that road.

topcat105

Thanks for the replies everyone. 
I left the heating on for an hour this morning.
Still no joy.
Radiator symbol flashes, syphon fill symbol, then nothing. Flame symbol disappears.
I rang the number on the WB page and went through everything.
He couldn't understand it so engineer booked for tomorrow.
Hopefully warranty will cover it....

Ayr_Rage

When a WB boiler is operating in syphon fill mode, it runs continuously at lower output with that symbol flashing until the level has been reached.

To generate condensate it has to operate the heating circuit with a certain difference between flow and return temperatures.

The pump runs and the heating circuit operates with the radiators getting warm.

It certainly does not run for just 30 seconds before shutting off and that symbol only shows when the filling process is in operation.

WIAWSNB

Ayr_Rage said:

When a WB boiler is operating in syphon fill mode, it runs continuously at lower output with that symbol flashing until the level has been reached.
To generate condensate it has to operate the heating circuit with a certain difference between flow and return temperatures.
The pump runs and the heating circuit operates with the radiators getting warm.
It certainly does not run for just 30 seconds before shutting off and that symbol only shows when the filling process is in operation.

Topcat - are you sure all the rad valves are open?! Turn them all up to 'max'.

(Or did the WB cove talk you through trying this?)

topcat105

Quick update for anyone who's interested.
Engineer arrived this morning.
Its the controls apparently.
I need a new control box and smart thermostat.
The warranty doesn't cover it as it's ESI not Worcester.  (Typical !)
I've just been quoted £150 by the original fitter so that's happening next week.
Thanks again for everyone's help and suggestions.