Electric warm air heating system any engineers in the house?

[jayc]

I think the fan is on the way out in my electric warm air heating system. Some times it fails to spin up and when it does its very slow.

Does anyone know if the fan is an easy replacement? The system is most likely the original from when the house was built (circa 1970) so even if its easy to replace I guess I may not be able to source one.

Also does anyone know if their easy to strip down and check the relays etc for the fan control system? I can't imagine there is much inside the huge box besides some brick, heating element, thermostat and some relays.

 

[RF Lighting]

I've not worked on warm air systems since I was an apprentice, but the ones I worked on were pretty straight forward.

Any chance of a couple of pictures? The motor may be ok, and just in need of a service and a clean. If not I would think you should be able to source a motor, or have the existing one rewound.

 

[ColJack]

if it's that old it might be time for a new replacement..

the newer ones would be much more efficient i should think by now??

 

[baz1968]

Neighbour has a similar system about the same age that is still going strong. Good thing about it is that it can blow cold air in the summer.

 

[ColJack]

this might fit if you're lucky...

http://cpc.farnell.com/jsp/search/productdetail.jsp?sku=MF6745261&N=0

 

[RF Lighting]

There is usually no need to replace the fan and the cowel, it is often just the motor which needs a bit of TLC

 

[ColJack]

you're going on the asumption that the fan and motor are seperate when in most small blowers, the motor is part of the fan and acts as it's spindle...

we use them all the time at work..

 

[RF Lighting]

We'll wait for the pictures.

I'll bet you a virtual pint

 

[ColJack]

to clarify, what are we betting on?

that the OP's heating has a seperate motor to the fan and that it's belt driven?

or that blower fans have the motors built in?

if it's the latter you need only look at the link i posted.. the motor can clearly be seen in the center of the fan blades..

we use from 0.5KW single phase, up to 58KW 3 phase ( the bigest we've done since I have been there ) blowers at work, but the motors are seperate after about 3KW..

 

[RF Lighting]

You can still seperate the fan (blades) from the motor in the link you posted.

I may have caused confusion by calling the fan blade cage thingy (the bit that spins round) the fan.

We'll wait and see

 

[markocosic]

If the fan/motor is a small induction motor and has ball bearings, like the one ColJack posted, chances are that it will use '608' bearings (roller skate bearings).


I rebuilt a 'Villavent' not so long ago that had this sort of thing (100W blowers) in:

http://cpc.farnell.com/jsp/search/productdetail.jsp?sku=MF67461


Four 608 bearings (enough for two fans) and postage from these guys was under a tenner!

http://www.bearingboys.co.uk/

If you unclip the circlip that holds the fan/rotor in place, it'll push/slide out. The bearings are a light press fit into the 'coil housing' of the motor - press them out and press in the new ones, press the fan/rotor back in, pop the circlips back on and you're away! There are some special washers behind the circlip. Fit these like this - () not like this )( or (( or )) - it'll be obvious when you have it in pieces.


Rebuild it *now* though - bearings are easy to do, but if you let the motor struggle/stay stalled for extended periods it can overheat and once the coils are toast there's nothing that can be done for it.

 

[jayc]

Great stuff guys!

I'll get some pics tomorrow. There's no obvious manufacturers name on the unit so I can't say what make it is.

Hopefully its as straightforward as you say and if I can't source a new motor / fan there is a rewind shop just down the road from my work so perhaps they can help.

Don't want to replace it as its worked great the past 3 years. tts in a well insulated 2 bed bungalow with no gas/oil and ellecy bills are usually £50 a month in the winter which I find acceptable considering I do
have a lot of other kit that is often on 24/7.

 

[jayc]

Update.

Unit is an Electricaire Enviwarm. Had a look inside it today with a torch and the fan is a cetrifugal type which is caked in dust and debris. The filter panel obviously isn't doing much!

If I get time at the weekend I'll whip it out and give it a good clean to see if that helps.