Power issue to central heating control unit

[FiremanT]

Nearly always a sub 20 minutes to locate fault.
Then the fun starts

And a multi meter is the "go to" tool.

Aptsys: I have recently noted a lot of your posts. What do you actually do?

You come over as either a know it all, a Dick or a "consultant". Or all three.

OP: You are clearly out if your depth. Contact a RGI, explain the problem and use your senses to determine if he is the right person to engage.
You probably will not get a quote but ask on what basis he charges. Assume nothing.
Good luck

 

[PullerGas]

Nearly always a sub 20 minutes to locate fault.
Then the fun starts

And a multi meter is the "go to" tool.

Aptsys: I have recently noted a lot of your posts. What do you actually do?

You come over as either a know it all, a Dick or a "consultant". Or all three.

I'm just two of the above.
But I must say; I do love whipping out my osilliscope. Failing that, I'll fall back on my 'holiday' multimeter.

 

[DP]

@aptsys , how do you think that ? I would use a multi-meter every time in this instance and never failed to find the cause yet, interested in how you would use other methods, happy to find other ways of any task

My sentiments too Ian.
The Flukey gets me out of trouble 90% of the times after the 10% working knowledge of what the boiler needs to do has been exhausted.

Simple fault, cannot see why this fault has become table tennis match

 

[Agile]

A multimeter will identify most heating faults.

However, there are some where testing the insulation at 500V with a Megger style insulation tester will be required.

But the OP seems to have caused another fault by blindly replacing fuses.

Fuses blow because of an excessive current and the cause needs to be found first.

 

[billybob150811]

could you call me a know it all too, I tired of being called stupid like the scarecrow I borrow other peoples brains someone must have said too me get a multimeter with continuity resistance and volts but not pnp transisters capacitance et al cause you don't know what your doing and you don't need them. but does anyone use IR I,d be interested to know id be more interested if you,d like to send me a fluke 1587 or such like. I sent my £25 to china several years ago and it still works fine

 

[DP]

My take on fuse popping is that it is 'heavy' short circuit that is dropping the 5 amp circuit breaker.
In other words, current drawn by the circuit is in excess of 5 amps hence the 5 amp breaker trips. If a £5.00 multimeter from a Christmas cracker cannot find this short circuit, clearly one needs to sit back and let a competent person deal with the issue

I have an insulation tester, can post picture of this instrument too as proof that I am adequately tooled up, but sadly this instrument has been useless over the years since the trusted Fluke 116 took up residence in the tool bag and has been able to deal with 90% of electrical problem, other 10% being working knowledge and experience

Billybob, I tried reading your post several times. Perhaps I can help?

 

[billybob150811]

I am always grateful for help I just wanted to know if anyone found carrying a meggar useful or is it just another tool to take up room without any real value I know how I usually find these and it should only take two fuses so I can buy a lot of fuses for the price of a meggar

 

[Steelmasons]

Failing that, I'll fall back on my 'holiday' multimeter.

You owe me a keyboard Dickie..
Holiday multimeter
You don't miss much eh Dickie..

 

[Steelmasons]

Disconnect all 240 volt components , grab a handful of fuses and power up controls , re-connect each component until fault is identified...easy ain't it...

 

[DP]

Steel that is where my 10% working knowledge beyond 90% meter usage for fault location kicks in. I forget when I used the meggar last. Perhaps I will need to dust it and do a bit of spring cleaning too. Does one even need to go far as disconnecting all the 240 volt components? Not for the first time have I removed the pump wiring cover to find water/ moisture in it, smell cover even to indicate coils that have been cooking to pin point a goosed pump, water on other mains components etc which if all fails, follow your scheme to locate duff component.