Myson fan-heaters

[flymofred1]

hello
i have an old myson fitted above the kitchen door which is plumbed into the c.heating. my problem is the thermo switch that senses when hot water is running round the system, has stopped working. the fan now runs continuously unless I switch it off. The local plumbers merchant said they were unable to help. Myson are only interested if I have a model no. fat chance! Can anyone help?

Thanks

FF

 

[Watchmaker]

I seem to remember that the model No and other details of the Myson which I used to have, were on the inside of the cover. Turn off the power, remove the two side screws and lift the cover off. There should be an identification label inside the cover.

 

[flymofred1]

I have had the cover off plus the whole thing off the wall nothing doing! it's clearly female 'cos it's one of lifes mysteries.

FF

 

[simond]

All I can suggest is taking the thing apart and looking for what is usually a small black component strapped to the flow pipe with two wires on it.

This normally has a part no. on it, which will not be a Myson specific part.

Check if it has failed with a multimeter. There may also be a relay, but these aren't used in most heaters.

Either ring up Myson with this detail, or go on line on Farnell, CPC or the RS Components website and see if you can find the actual component.

Alternatively, buy a new heater from Smiths www.smiths-env.com, comes with a 5yr warranty.

If the Myson unit is old the fan will be getting noisy anyway.

 

[flymofred1]

I taken the switch off and with the aid of my daughters microscope (I'm getting on a bit) read the following.


agear
T1PO-O T180 K11

I've tried 'Googling' various combinations no luck. There is no model no. for the heater.

Thanks

FF

 

[Joe4542]

You would want something along the lines of this

Thermal Switch

The web page has errors in listing -it appears they got confused with opening/closing specs!

Basically you would want a thermal switch that is N/O (normally open), that closes at ~40c to switch on fan (presuming there is no fancy relay switching system), and the switch then opens again at appx 25c when the water flowing cools.

If you were to fit one - thermal paste would be preferential between pipe an switch

Joe

Edit : as Simond says above test old one first (might not be faulty!), Should prob read open circuit at room temp, and then show continuity when heated (dunked in hot cuppa!)