problems again and so I am back

[fulcrum]

Last time I had problems you were all immensely helpful so here's hoping again.

I have an old Potterton netoheat 10-16. It seems to have been working this morning because I have full tank of hot water. It was ok yesterday evening.

The house was cold so I turned the boiler on to heat the rads. Result loud screehing noise from the boiler but it fired for about 30 seconds then cut out. Ditto a bit later. Hot water then backflows to the header tank.

This was similar to my last problem when I got an air lock after a disaster replacing a rad. However not touched the system this time (never again.)

Last time I got the air out eventually to get the system to work but had to get a professional in to sort it out the rad. He eventually diaganised a blocked cold feed pipe which he repaired, along with the header tank valve and cleaned the pump etc. £550 thank you. (He was there 6 hours)

There does not seem to be any air in the rads or the pump. I can find no leaks. The pump is working. The 2 port valve I know is kackered as it heats the rads when on water only. The header tank has water in it and the valve is working.

I suspect you are going to tell me the cold feed pipe is blocked again but why would that make a difference since I have not drained the system?

Not unreasonably I can not get hold of my usual H&C corgi man. Any suggestions?

 

[corgigazza]

possible fan bearings gone requires new fan,listen to boiler when calling for heat check for fan noise new fan retails 145+vat

 

[fulcrum]

thanks - the fan is OK. I have put in a new pump which has helped a bit. The feed is ok. The return is cold to the boiler and from the cylinder so I guess there is a blockage there. Cutting it out is going to be pig and not something I will attempt. is there any tricks of the trade which might help.

 

[ArtfulBodger]

powerflush it? at least you will know if there is a blockage or not then

 

[fulcrum]

Wont that be rather expensive? Though I guess in the long run.............

 

[kevplumb]

fernox ds 40

 

[corgigazza]

to check cold feed open drain off cock on rad and see if tank fills up , also have hade 2 port vave cramed full of dirt not letting flow happen when valve opened manual

 

[fulcrum]

Thanks- did that check of the cold feed. Its ok.
I know the two port is knackered so will try and replace it.

 

[fulcrum]

Well I still have heating but to maintain heat to the rads I have to bleed every day at least once. A massive amount of air is being dragged in - no doubt from the F/E - why?

 

[fulcrum]

I realised that this new pump was far more efficient than the old one and have now put it on the correct setting of 1. Now have good heating and water without the noise but it still requires a daily bleed from the first rad!!!

I think I will wait until the spring and replace the boiler converting to a fully sealed system. I have a 2 bed roomed flat with 6 rads so about 40000 BTU. Any recommendations for a new boiler? etc

 

[doitall]

hold a glass of water under the openvent, and turn the boiler on does it suck the water out the glass