Thread: Air compressor won't turn on

Is there a red button on top of the Pressure switch? You may have accidently knocked it which would turn it off, it should be up from memory

ahhhh...the old "compressor won't start up" problem.

Mine did exactly the same. I was told (by a compressor repair man) that this was because I often turned it on and off at the mains, rather than using the red switch on the unit itself. On his suggestion, I tried fitting a new starting capacitor to mine which made it work for a few months, but then it died again...

Suffice to say I now have a new compressor, and I ALWAYS switch it on and off using the red button rather than the switch on the mains socket.....

Mr Brush,

So, capacitors you reckon, mine has two huge mothers inside the plastic box, atop of the motor. I have always started and stopped my compressor via the red button, so lets hope my problem is more simple.

Just tried it again, still no go.

Ken

Superworks.....!!!!!!!!!!!!!!!!!! Well that should answer your own question..!!!....lol
But you have prob sneezed a pressure switch,redily avaliable on EBAY.

Hi Matthew_g

I bought the compressor off a chap in the bush not knowing the first thing about compressors, let alone "Superworks". Thanks anyway for the tip re pressure switches ex eBay.

How can I test the unit to determine what is wrong?

Ken

Take the cover off the little black box where the red switch is,and there will be a pressure adjustment screw.
If you turn it one way you will lower the start pressure and the opposit will raise the start pressure.
I hope for your sake that is all that the problem is.
Matt

Search all over the thing for a reset switch. My Able Cooke did this to me one day and after a lot of searching I found a small reset switch that had tripped.

These cheap compresors vary a bit in features - mine didn't have a reset button, and being a smaller compressor only had a starting capacitor. The bigger ones will have a running capacitor as well - you'd have to work out which is which.

Its easy to determine if the problem is anything to do with the switch. Here I'll insert all the usual warnings about making sure the thing is unplugged, use a licensed electrician, etc.......

Dump some air from the compressor tank so that it is nowhere near full, then you can bypass the entire red button/pressure switch assembly. Mine had clearly coloured live, neutral and earth wires on each side of the switch assembly. Disconnect the wires and join live-live, neutral-neutral, earth-earth using a terminal block. The switch is now out of circuit. Plug the compressor back in, and BRIEFLY turn power on at the socket to see if it runs. If it does, the problem is somewhere in the switch/pressure sensor. If not (as happened with me) the problem lies elesewhere. Obviously, with the pressure sensor out of circuit, only apply power briefly to see if she goes. DON'T leave it running, as the compressor now has no pressure sensor in circuit !!!!!

Doesn't take 10 minutes to do, and might save you buying a whole switch/pressure sensor assembly for no reason.

The guy I spoke to said that unless you can fix these cheap compressors yourself, just junk it and get a new one. Repair charges (+parts) comes pretty close to new cost.

ants like to build in pressure switches, stuffing them up, well they do here...

I thought I'd fixed it, but now I'm not sure. It is the pressure switch. For some unknown reason, the contacts inside the plastic cover were being held open. One push with a probing finger released the contacts allowing them to move freely. The compressor now starts, but doesn't look like stopping, the tank pressure gauge indicates nearly 120 psi, getting into the red. I switched it off prior to this and am not game to go further.

According to the manual, it is supposed to cut out at 115psi.

My compressor lives inside, and is ant free, I think.

Any further ideas?

Thanks guys for all your advice so far.

Ken

If you want to use it as it is untill you either fix or replace the pressure switch you can.
I would suggest that you adjust your POP OFF valve down to 115 PSI and let your compressor run untill you have finished what you wish to do.

Thanks Pipeclay.

What can possibly go wrong with the pressure switch, is it serviceable? Apart from the heavy duty contacts, which look fine, all I can see is a big spring with possibly some sort of rod running thru the centre of it. I presume this rod is some sort of piston acting against air pressure.

Ken

I wouldnt have a clue unless the contacts are dirty.
Mechanically the Rod will apply pressure to a Spring which inturn applies pressure to a valve.
The more pressure on the Spring the higher the pressure before it cuts out and vice aversa.
Shouldnt really be a mechanical problem unless the Spring or Valve are faulty.
In the past when mine have played up I replace the unit.

sounds like the diaphram that actuates rod is suss if it is its usually easier to replace the pressure controller