changing from warm air heating to radiators

George_Bray

hairy_g wrote: »

I could replace it but because I'm not in the trade there would be no guarantee.and for the sake of £60 quid I get 12 months Guarantee and someone gets a couple of hours work.

I have a similar system to yours and I've removed the fan assembly several times to blow dust out of it. A couple of years' ago I built up an understanding of how the system works so I can hopefully get it working again, if it ever fails. My system is now over 25 years old and has never been serviced or 'tampered with' by British Gas or anyone. That's why it's still working OK.

I was also interested to read on the J&S website that these heaters are not covered by the boiler scrappage scheme, even at 25 years old, and with an inefficient pilot light which is always on, because they are deemed too efficient!

Anyway, I must find the notes I made on my observations but I had the fan running on my kitchen floor, on its own, by applying electricity direct to the fan motor. 230V mains I think, but check. You could use the same approach to check whether the motor really has failed. Two other parts which could have failed are the motor start capacitor (very cheap) which I think they may have, or the main PCB control circuit. I don't need that PCB in order to get my system blowing warm air and it's probably the weakest link in the whole system.

Good luck.

C_Mababejive

Just to add that a good/well maintained and installed FWA unit,preferably with a circulator/well lagged cylinder,will serve most homes well. If yours is a few years old then it is likely to be open flued. i.e the flue is a kind of chimney arrangment off the top/back of the heater. If you have one of these it is absolutely imperative that you have it serviced by someone who is familiar with FWA units,that they check the integrity and security of the flue,return air ducting and ventilation and that you have a CO alarm fitted.
http://news.bbc.co.uk/1/hi/wales/8166245.stm

Note that there are undoubtedly hundreds of GSR registered installers who are of younger years who have had little or no experience of FWA units and may not have FWA registration on their cards!

Gerrard_8_lfc

my Warm Air Unit is serviced every year by BG but I would not trade it for a combi if I got a new boiler for free.

First hand I have not booked a job for a broken warm air unit since I started with BG and my own is a good old boiler.

Combi boilers like new cars the more they do the more that can go wrong with them. plus the rads.

C_Mababejive

Gerrard_8_lfc wrote: »

my Warm Air Unit is serviced every year by BG but I would not trade it for a combi if I got a new boiler for free.

First hand I have not booked a job for a broken warm air unit since I started with BG and my own is a good old boiler.

Combi boilers like new cars the more they do the more that can go wrong with them. plus the rads.

There is a lot of truth in what you say. I can still remember the days of very simple eastham Maxol wall mounted BF circulators with low input which provided a full tank of hot water and very reasonable cost. Now we have 40Kw combis making unreasonable demands on gas and water supply networks,wasting fuel and often not even meeting the HW requirements of a family home whilst being overly complex and expensive to run and maintain. And yet by some kind of marketing trickery and received wisdom,people have been convinced that they are somehow more efficient !

hairy_g

Should I have been surprised? I left work at 12.00 got home for 12.30 to find the engineer had called at 12.18. he was booked to call 1pm to 5.pm !!
called the company and they left him a msg to call back to my house, he never turned up! :mad: I have now left a msg on their phone asking how they will resolve this.
will post tomorrow.

George_Bray

mealticket wrote: »

george, i hope you have also built up an understanding of how dangerous these units can be if they are not maintained properly. good luck playing with 230v

What dangers? I monitor the surroundings for carbon monoxide and the meter hasn't registered anything yet. I've been "playing with 230V" since I was about 12 years old, and am not about to stop now. It's predictable that traders will put out scare stories in order to deter most people from doing what I do.

George_Bray

C_Mababejive wrote: »

it is absolutely imperative that you have it serviced by someone who is familiar with FWA units,that they check the integrity and security of the flue,return air ducting and ventilation

I'm sorry to say this sounds like money for old rope, a bit like most car servicing where it's just a paid-for opportunity to prospect for further work which probably doesn't really need doing. I agree about the usefulness of a CO alarm but that surely applies to any heating appliance. If there's a problem with the exhaust it will either show up as CO or you might smell smell something, I guess. If there's no detectable threat, what problem can there be?

George_Bray

mealticket wrote: »

ythe fact that you aren't familiar with the consequences of lack of servicing doesn't mean that there aren't any.

Thank you for highlighting some potential issues. Are the flues/chimney/exhaust systems on these specific warm air systems (mid 1980s models) really that bad? I'd be grateful for a bit more information. Does the chimney get coated with deposits which can then catch fire, or something like that? How can a service engineer see up there, and what can he do about it? What else is typically done during a service, besides blowing dust out of the wire mesh filter and blower fan?

Apart from those latter two dust blow-outs I don't actually do anything, although I'm sure you're right that an insurance company would wriggle out of any claim, if they could.

George_Bray

mealticket wrote: »

the problems begin when the burner, or even the pilot flame, starts to run 'dirty' (incomplete combustion) through lack of servicing. the soot produced tends to accumulate at the top of the heat exchanger, to the point where it gets completely blocked,

I trust I'd smell any exhaust coming back into the room but I haven't noticed anything amiss at all and my CO alarm has never sounded. Are there any measurement devices for assessing the purity of the main burner and/or pilot flame?

I've seen some warm air heaters in the front gardens of houses, where they've been replaced. It's one large, heavy box. Perhaps I could take mine out in the summer, give it a really good clean and check for any blockages in the flue or gas jets, before putting it all back. This would go much further than any service on the flue by a professional.

C_Mababejive

George_Bray wrote: »

Thank you for highlighting some potential issues. Are the flues/chimney/exhaust systems on these specific warm air systems (mid 1980s models) really that bad? .

No they are not bad. They just need expert installation and servicing. Lots of local authorities flew into a panic in the 80s/90s and binned many CF FWA units. There had been a number of.......ermm....accidents and deaths due to FWAs. Most of these were ,in all fairness,due to poor installation and poor servicing ,mostly relating to flue integrity,Return air duct issues and ventilation issues. But then similar issues could exist with a gas fire or any flueless/non room sealed appliance. One of the biggest dangers is if the fan unit is allowed to create a negative pull on the flue. In this case,it sucks down on the flue and redistributed the products of combustion throughout the house via the warm air outlets