central heating problem.

[only_tony]

Hello all.
I have a problem with my central heating. My boiler is a Vokera 24/96 R S E Flowmatic. It operates fine for hot water but when I select the central heating it lights for 15 seconds then goes out for a minute, then repeats. As a result I can only get heat to one radiator, the closest one. If I shut that radiator down then the heat will start making it's way to another radiator but I only seem to be able to get one radiator on at a time. Does anyone have any ideas as to what the problem might be? Thanks

 

[only_tony]

I've done a search for Flowmatic and read all the pages. Can't seem to find a problem similar to mine. They all seem to be loss of either hot water, central heating or both. Apart from the lack of circulation to the radiators the boiler appears to work fine. I was starting to suspect that the pump might have failed, although it is still spinning but in one post I read it was said that if the pump had failed the boiler would not operate. Does anyone have any suggestions please?

 

[ChrisR]

Check the air vent os open - it's sort of through the middle and up behind, to the left
Is the boiler getting up to temperature??
Does it stay on more/less according to the temp setting on the front?

 

[only_tony]

Praise the lord,I was about to go to bed. Air vent is open. Boiler flow pipe gets very hot and as I say I can get heat to at least one radiator. I have listened to the boiler and there are no sounds of "kettling" just before it cuts out. Have been here five years and this is the fist time we have had any problems with the boiler

 

[ChrisR]

Does it stay on more/less according to the temp setting on the front?

 

[only_tony]

Sorry I meant to say in previous post that temp gauge is broken. I'm into the Southern Comfort and Coke so I may vanish at any moment. I would just add that flow pipe in vicinity of boiler red hot to the touch.

 

[only_tony]

Sorry, I have to go. too much SC and coke. Will pursue this further tomorrow before deciding if it's time for a new boiler. thanks.

 

[DP]

It is due to lack of circulation in the heating loop.

The pump operation is checked by another component but if boiler has not been serviced regularly, burner can actually come on with a dead pump. In this case you would have no HW either.

Can you post your location?

 

[only_tony]

DP. I am in the north east of England. Going to do some serious browsing and manual reading today to see if I can find a fix. I have a number for a local company who apparently work on these boilers but that will have to be a last resort as I am pink lint at the moment.

 

[only_tony]

Two and a half hours browsing the web and reading the manual. I need a break as my eyes have gone funny. Out of curiosity, would this problem be caused by a failure of the pin in the diverter valve to return to its normal at rest position?

 

[only_tony]

Have spent the best part of today researching boiler problems. I suspect that my particular problem may be related to the diverter valve and it's associated bits. Apparently I can get a repair kit so I'm going to give it a go. Can't be any worse off than I am now. O.k so I could lose the hot water as well but I've got a leccy shower. Will post back and let people know how I get on just in case anyone has a similar problem in the future.

 

[only_tony]

Update. While staring at the boiler in the vain hope that it would fix itself I decided to put the heating on. Noticed that bathroom radiator was starting to get warm so turned off bedroom radiator. Long story short, went round closing radiator valves until I got them all hot. At this moment all are still piping hot. Boiler now running for 20 seconds off for 40. I'm more baffled than I was earlier when I thought I had the problem sussed. Just going to hope that it will keep running until I can get some cash together for someone to have a look at it. Still open to any suggestions in the meantime.

 

[twgas]

i would suspect the diverter, to check it:
1) let boiler cool right down
2) turn heating on, do not run any hot taps
3) when burner shuts down feel secondary heat exchanger, if its hot your problem is the diverter.

 

[DP]

You nearly there. Email me for part number.

Do not give up. Having fixed the boiler, then you will be able toast the boiler with a shot of SC