Kickspace heater thermostat

[Tim+]

Our Myson Kickspace 500 heater has taken to sometimes not spinning up when the CH is on. There’s an internal normally open stat that detects the flow temperature to turn the fan off when the central heating goes off.

With the heater out on the floor and the CH on, the fan runs, but unevenly, and I’m wondering if the contacts in the stat have become a bit “iffy”.

The stat is a small two terminal “button” shaped thing that’s clipped against a pipe. A pretty standard component but I’m not sure of it’s proper name.

It has F41C 9958 5 Z14 08 stamped on the face of it (the face that is applied to the pipe).

Would I be right in thinking the 41C is the closing temperature? I’m guessing 08 might be the year of manufacture.

I can probably get one from Myson but just wondering if there would be cheaper alternatives. Knowing the correct name and nomenclature of this type of stat would help in my searches.

Tim

[whisky-dave]

Picture would be nice but does it look like this

41C sounds to specific, when 42 would be the answer to everyfing ;-)

I'm not sure if numbers of these things make logical sense.

a google searcdh for the number gave me this but not that useful either.

[Tim+]

It’s that kind of thing although mine is normally open at low temp, and then closes once the temperature rises above a certain level.

I decided to phone Myson who think that the stat is unlikely to be the issue. They either work or they don’t, they don’t “half fail” with poor conductivities and they suggested that the motor speed variation is more likely down to just the age of the motor. Apparently the stat should close at 31C.

After this conversation I shorted out the stat and indeed the motor speed did still wander about a bit (on the low speed setting) which fits with what they said.

Not sure why it’s just not starting sometimes. May still be a motor issue but to complicate things I have an external wireless room stat also controlling the supply to the fan so I may need to delve into that.

Tim

[Rob Morley]

I'd suspect crusty lube in the bearings, or just badly worn bearings.

[Tim+]

That was my first thought but the fan spins freely and silently if I give it a poke.

Tim

[Rob Morley]

It's not a brushed motor is it?

[Tim+]

No, brushless. I think it’s what’s called a “squirrel cage” motor.

Tim

[ARW]

:-)

Very good

[Owain Lastname]

You need a solenoid then to give it a poke automatically on call-for-heat then :)

Owain

[Rob Morley]

A solenoid controlled valve hooked up to a compressed air source to blow the fan into action might be easier to arrange than a mechanical prodder. 8:)

[Animal]

Age isn't really the cause. Bad lube can cause stall, slow speedup, reduced speed & overheating, but not often wavering speed. Bad bearings can cause speed wavering, but are very noisy. I'd clean/lube the bearings & suspect the dropper if there is one, but more likely there isn't.