Hello,

The combi boiler in my new house has just packed up. I downloaded a
manual from the manufacturer's web site, which includes a fault
finding flow chart. There is 240v at the fan but the fan does not
turn. It seems a bit stiff when turned by hand. Is this just age? Does
it dry out in the heat?

The boiler is a sime. I've never heard of these before. Are they any
good? I don't know how old it is but it is not a condensing boiler.
There is a little rust on the one side and some green on the copper,
so it must be a few years old.

Thanks,
Stephen.

On Tue, 16 Jun 2015 09:26:17 +0100, Stephen wrote:

There is 240v at the fan but the fan does not
turn. It seems a bit stiff when turned by hand. Is this just age? Does
it dry out in the heat?

No, should not be stiff; yes, age; yes. Sounds like the bearings are worn out.

Try something like wd-40 on the bearings: if it works, even if marginally, the
diagnosis dried out/worn out is confirmed. The wd-40 will not effect a repair,
it will seize again within anything form minutes to days. But it may allow a
confirmation that the fan is seized and there is nothing else keeping it from
working.

Go to www.cetltd.com and get a reconditioned replacement. If in doubt as to the
diagnosis, mail them. Geoff is the boss and was a regular here at uk.d-i-y, and
he knows fans 'n' things.


Thomas Prufer

On 16/06/2015 10:28, Thomas Prufer wrote:
Go towww.cetltd.com and get a reconditioned replacement. If in doubt as to the
diagnosis, mail them. Geoff is the boss and was a regular here at uk.d-i-y, and
he knows fans 'n' things.

Another vote for Geoff here.

Andy

On Tue, 16 Jun 2015 11:28:22 +0200, Thomas Prufer
wrote:

Try something like wd-40 on the bearings: if it works, even if marginally, the
diagnosis dried out/worn out is confirmed. The wd-40 will not effect a repair,
it will seize again within anything form minutes to days. But it may allow a
confirmation that the fan is seized and there is nothing else keeping it from
working.

Go to www.cetltd.com and get a reconditioned replacement.

Well as it happens, that's exactly what I did. Whilst I was typing my
message I had 3 in 1 soaking into the fan and it now spins quite
happily.

The brand new parts are 170ish ex vat. How can a fan cost so much?
They don't cost that much in any other appliance (hair drier, oven,
computer, fan heater, etc).

A reconditioned one seems the only sensible way to go. I had heard cet
recommended here before and I have contacted them for a quote.

How do these fans work? I'm thinking with a dc motor if you connect
the power the wrong way round, the fan will turn backwards but how
does it work with ac. (I forgot to take a photo before I pulled the
fan off and I can't remember which way round the wires go! it seems to
be blowing out the flue so all seems to be well).

Thanks.

On Wed, 17 Jun 2015 14:33:08 +0100, Stephen wrote:

Well as it happens, that's exactly what I did. Whilst I was typing my
message I had 3 in 1 soaking into the fan and it now spins quite
happily.

The 3-in-1 will work for a while, but not as well as new bearings. (I'm guessing
bronze bearings.)

(Geoff will take yours, clean it up, pop new oil-soaked bronze sintered bearings
into it, test it so he can guarantee his work, and sell yours on. Meanwhile you
will get one he's already done that to, IYSWIM.)

How do these fans work? I'm thinking with a dc motor if you connect
the power the wrong way round, the fan will turn backwards but how
does it work with ac. (I forgot to take a photo before I pulled the
fan off and I can't remember which way round the wires go! it seems to
be blowing out the flue so all seems to be well).

Without knowing what the fan motor looks like, I'll guess and say

https://en.wikipedia.org/wiki/Shaded-pole_motor

Thomas Prufer

The brand new parts are 170ish ex vat. How can a fan cost so much?
They don't cost that much in any other appliance (hair drier, oven,
computer, fan heater, etc).


The price of parts makes all-inclusive callout charges almost look like
good value.