Heating only works when the water is switched on

[cmaskelyne]

I have a Baxi boiler and a potterton control unit. Recently I have been adding some radiators to the system and have drained down and filled the system up several times without problem. I drained the system down last week to move one of these radiators and refilled it. Unfortunately I went out of the night but my wife said she heard a screech from the boiler cupboard (not sure which part). When I got in I checked for airlocks in the radiators and found a couple still had some air in.

Anyway the system now does not make a noise but the central heating will only come on when the water is switched to "on". Everything appears to work perfectly then but obviously we should be able to have them on even with the water off.

Can anyone point me in the right direction. I am a reasonable competent DIY'er but not highly techinical on boiler parts. Is this something I should attempt to fix or get a plumber?

Any pointers should be great.

 

[kevplumb]

Can anyone point me in the right direction.

well you could start by pointing us in the right direction

boiler make/ model

system type and controls

 

[cmaskelyne]

It is a Baxi Solo 3 PFL 60 Boiler

I am not an expert on type of boiler - it has a large hot water tank to the side with a Potterton Controller above it (Mini Minder) for turning the water on and off, etc. There is a small silver box (Honeywell - F5-9336 with an auto/open setting) which I have just set back to Auto as it was inbetween the two (wife may have knocked this when she put something back in the cupboard). There is also a red circular Grundfos device attached to the pipe - looks like it may be the pump.

When draining the system down I turned the feed off in the loft to the header tank and once finished filled it back up. Went round each radiator twice to allow the air out of the system whilst the heating was on and pumping water.

Hope that helps.

 

[cmaskelyne]

I have read on several posts that this could be a divert valve issue? Am I barking up the wrong tree here? How easy are they to change?

Any help gratefully received.

 

[bengasman]

First guess is an airlock, it would be a bit of coincidence if the diverter had died, but it is possible.

 

[cmaskelyne]

Thanks I did wonder about that - I have released all the air from the radiators and they all appear to get hot/warm can I do anything else. I am a reasonably competent DIYer but not an expert on plumbing.

Thanks for any further help you can provide.

 

[bengasman]

The airlock can be in the pipes that are exclusively for the cylinder.

 

[cmaskelyne]

If that were the case is there an easy way to clear this?

 

[bengasman]

Look for a bleeding point. Failing that, try a back fill with the ch valve closed and the dhw valve manually opened.

 

[vindev]

Hi Guys, I have a Honeywell Timer ST6400c, Honeywell thermostat T6360B and a Potterton profile 80e heater. Poblem is the timer and boiler ony fire up for hot water. Cannot get the boiler to fire up for heating only. Boiler fires first time for water with or witout timer but nothing for heating. Any help appreciated.

 

[kevplumb]

start a new thread

you will only cause confusion hijacking

 

[bengasman]

Hi Guys, I have a Honeywell Timer ST6400c, Honeywell thermostat T6360B and a Potterton profile 80e heater....

And the relation to this thread is?

 

[welding3]

Hi Guys, I have a Honeywell Timer ST6400c, Honeywell thermostat T6360B and a Potterton profile 80e heater....

And the relation to this thread is?

Have I pushed in aswell? If you can help Similar thing with Potterton Puma 80, it wont fire up on central heating but works OK on hot water, have checked the pressure is OK at just over 1 bar. Help. Ideas?

 

[bengasman]

Hi Guys, I have a Honeywell Timer ST6400c, Honeywell thermostat T6360B and a Potterton profile 80e heater....

And the relation to this thread is?

Have I pushed in aswell? If you can help Similar thing with Potterton Puma 80, it wont fire up on central heating but works OK on hot water, have checked the pressure is OK at just over 1 bar. Help. Ideas?

Yes, got a great idea. Start a thread with the header: puma with no dhw.