Boiler not lighting since I fitted a new radiator.

[Terence Johnson]

We have a 60s house with a single pipe central heating system
About 3 weeks ago I went into the loft as I was going to fit a new radiator so I planned to block the breather and feed pipe in the central heating header tank. To my surprise the water was boiling hot.
I shut down the heating system and called British Gas. They quoted a two day delay so we switched to our immersion heater.
Engineer called and advised we had rust in the pipes causing a partial blockage. Said we needed power cleaning which would probably mean I should change our old but reliable Potterton Netaheater 50e boiler to.
Why I have been pondering on the quote I drained the system and fitted the rad. Now the boiler will not light. I have bleed the rads and the pump. When I switch the heating on water circulates out of the header tank and re-enters via the breather. Boiler is dead. The boiler has a drain plug in the heat exchanger from the parts diagram. Do I need to undo to see if water has circulated to boiler?
I am half tempted to just buy a boiler as you get a flush but all the previous engineers have said what a great boiler... any thoughts would be appreciated. I am new to the site so hope this question is OK to post

 

[terryplumb]

Sounds like you have a blockage on the feed from the f&e.
Does boiler try to ignite and then goes to lock out ?

 

[Terence Johnson]

Boiler is just dead but it must have very briefly lit once after I refilled the system as we have a small kick panel heater in the kitchen next to boiler and it briefly cut in once (the fan only blows when it is warm).
I'm no plumber but been in the motor trade so can do most things once I have located the problem.
Thanks for responding..

 

[terryplumb]

Have you tried to reset the boiler ,by pressing the re set button ?

 

[Terence Johnson]

Your a star... reset button had worked. Thanks. I did try earlier but had not pressed it hard enough. Many thanks.

 

[terryplumb]

It has obviously overheated at some point , almost certainly due to lack of water in it / in the system. Which is really what you need to sort out . First place worth checking is the first "T" on the feed from the f&e tank. Post some pics of pipework maybe ?

 

[Terence Johnson]

All rads are now getting hot, the header tank however sounds like Niagra falls down stairs with the water flowing out of the breather pipe at pump speed. The BG engineer turned the pump down to 2 but did say it might stop rads all getting hot.
I've taken pics. I did look in my Collins book of how to do everything ....lol... but just got more confused.
I must say the boiler sounds like a Rolls Royce, quite and working lovely.

 

[denso13]

sounds like Niagra falls down stairs with the water flowing out of the breather pipe at pump speed.

Definitely sounds like a blockage from the feed and expansion cistern, commonly in the area marked below. Someone may already have had a look where the compression fitting is.

 

[terryplumb]

With a strong magnet ,and starting where the feed pipe from the f&e comes down thru the ceiling ,run the magnet slowly down the pipe.The magnet will be attracted to any blockage of magnetite in the pipe.

 

[Terence Johnson]

Thanks again.
The BG engineer did use a magnet somewhere in that area when he said I had rust blocking the pipe. After he left I got my super neodymium magnet out and I couldnt feel any magnetism there so I wasn't sure if he was correct.
Interestingly I have just put the heating on again and currently there is no flow back in the tank. If it is a blockage would the fault only show up up when hot or has my Fernox powerflushing cleaning F5 fluid fixed it?
Im going to do as you say now with my magnet.. sorry to sound a but thick..lol I used to work on a car technical helpline so know what it's like speaking with people that are not that knowledgeable in the subject.

 

[Terence Johnson]

Quick update.. fault is still there. The water is returning to the expansion and feed tank at radiator temperature. My flushing cleaner has failed but I guess it could take a few days to work.
I will ge a local plumber out as blockages are not covered by my Brit Gas 3 star cover.
Appreciate your help guys.

 

[muggles]

I will ge a local plumber out as blockages are not covered by my Brit Gas 3 star cover.

Time to cancel that cover and put the money in your own bank account instead. As you've now discovered, they're quite happy to take money off you but when your system starts getting a bit old they'll try to sell you things you don't necessarily need and refuse to cover some of the problems you do experience. You'll get much better value for money by keeping that cash in a rainy day fund and paying a trusted local tradesman when you do need work doing.

 

[Terence Johnson]

I'm going to ring our local plumbing company who i have used before and trust. I'll let him diagnose and fix and i'll ask if he thinks I should replace our trusty old boiler.
I have turned the pump speed down to 2 which has slowed the hot water returning back to the expansion tank.
To be fair British gas has been faultless until now. Over the years they must have replaced just all of the wear and tear items FOC . This is the first time they have not fixed the fault.