Sime Super 90 - not working!!!

[karl0202]

Hi everyone.

Really need your expert advice here. Just ran the bath for the kids to find NO hot water. Tried the CH and again nothing.

Had a look at the boiler. I'm not too bad with electrics but I've made sure i've not touched the gas. Cover off and multimeter in hand. Ran hot tap. Checked the electrics and I've power at the 3amp fuse and into the board. The pump was working but the fan was not. Checked at the fan and there's no volts there. Noticed 2 little fuses on the board (who on earth designed these things -credit to you installers when you fix them)

Any ideas. Is it one of the PCB's or am i missing something else to check first???

 

[gas4you]

Don't know this boiler, but if no power to fan then it is obviously fault before this point. Have you checked/replaced these 2amp pcb fuses? Could be fan knackered and blown them, or as you say could be the pcb its self.

 

[scatmanjohn]

Whats the pressure reading...I have had these doing all sorts of daft stuff if the pressure is too high or too low.

 

[Agile]

Has your boiler got a plastic diverter valve with a system flow switch towards the left?

This has to be made before the fan will start.

Tony

 

[karl0202]

Scatman: Pressure when cold is reading 1.5mbar.

Agile: Not sure. Just had a look. Diverter valve looks like its near the back. Brass fitting with circular ring on top. Has a ? black square switch sitting on the top.

Gasforyou: thanks for the advice. Already seen the 2 fuses on the PCB. I took them out and got continuity across them both. Same with the 3 amp fuse.

Look forward to more advice.

 

[Agile]

You need to identify a system flow switch and see if its operating when the pump comes on.

Tony

 

[karl0202]

You need to identify a system flow switch and see if its operating when the pump comes on.

Thanks Agile. Any idea what i'm looking for or where it would be situated on this boiler. Pumps on the right and behind is the diverter valve.

PS: if i find the flow switch, how will i know if its operating. Do i use a multimeter??

Thanks for all the advice. I dont mind looking around but if anything needs removing when i identify the fault - time for RGI

 

[karl0202]

where is the flow switch on this boiler??

 

[gas4you]

Can't find any reference in your posts to say whether pump is actually coming on? Have you checked this or have I missed something in a post here?

 

[karl0202]

Hi gasforyou. The pump is working ok.

 

[karl0202]

Is there a flow switch on this old boiler??????

Like i said. pumps working. Power to the board but getting nothing at the fan which refuses to spin......

 

[gas4you]

As I said I don't know this boiler but I've just checked the parts arena breakdown for the original and mk2 versions and cannot see a flow switch listed!!

Check if power is getting to ignition control board on the gas valve I think on this boiler.

 

[karl0202]

Gasforyou: thank you for looking. I couldnt see a flow switch either. It wa 'Agile' who thought there may be one and that it powered 'proved' the fan.

I think it therefore may be the ignition board that needs replacing.

 

[scatmanjohn]

Forget owt i said..i was thinking of the sime planet (or whatever its called)

Overheat stat hasn't popped out has it?

Little red button under boiler, try pushing it.

 

[Agile]

Its not the one I took out today with a plastic diverter valve.

It may be the earlier one with the red o/h reset underneath and the diverted in the middle and gas valve on the lsft and pump on the right!

Good likelhood of being the o/h stat underneath.

Tony