Ideal Icos m3080 blowing fuses

[windbagUK]

Have an Ideal Icos m3080 with no internal pump (only external)
It had failed with L8 code.
FanDC volts were low, so PCB needed replacing.
Have bought refurbed PCB.
Also thought it best to get new fan as I read here that these can be an issue, taking down the PCB. New fan resistance 106 ohm, & certainly looks new.
Just installed both, but it blew mains supply 3A fuse.
A couple of more tests, and on third blown fuse, the PCB fuse has also gone.
I've now run the external pump from separate supply with 3A fuse - no problem.
All other non-boiler mains eqpt connected, no blown fuse, so it must be internal to Icos.

Any ideas welcome.
(Off to Maplin, who show 3.15A quick-blow fuses in stock)

 

[DP]

A sharp kinife and hara kiri comes to mind when linked to ideal boilers.

 

[windbagUK]

Would that I had known that when it was bought!

The sad thing is that the unit is very clean, virtually no corrosion, no sign of any leakage of any sort from any component.
It's certainly cleaner than my PC and most HiFi components I have opened up.
The worst degradation was the presence of a dead spider and web fragments.
So, for the want of working sub-units, we're confined to rooms with heaters.

I've now got some spare fuses from Maplin, so if anyone can suggest anything to try (short of suicide or junking it) I'd welcome more suggestions for tests or measurements I could carry out.

 

[Agile]

I thought that Amy of Homeserve was going to sort out a fixed price repair for you?

Tony

 

[SortedPlumbing]

Diy gas repairs gone wrong.

You might want to re post in diy disasters section.

You've just cost yourself a small fortune.

 

[DP]

Windbag, the circuit boards are highly complex when
LSI chips are used as they are on this board. Even majority of Ideal chaps nd ladies would be hard pushed to decode the programme housed in the chips on the PCB. To think someone out there with nothing more than a multimeter and a soldering iron could refurb such a board stretches the imagination somewhat. I as a heating engineer would want to plug in a new board that has not been touched by someone who thinks they can refurbish complex boards

Good luck in your quest to get this dragon to breath fire again

 

[45yearsagasman]

View media item 36533It will fit nicely in there, if you get fed up with throwing parts and money at it.

 

[onecog]

View media item 36533It will fit nicely in there, if you get fed up with throwing parts and money at it.

Untitled

• onecog
• 24 Mar 2013
• 1

They won't take them now

 

[windbagUK]

Yes, very good, folks, but I thought this was a DIY support forum, not a place for taking pot shots at someone with a broken boiler in the snow.

Is it feasible to power up the PCB with some of the other systems unplugged to see which is causing the excess power drain?
eg power it up with fan & gas valve modules unplugged (others?)

I know which the fan plug is (at the PCB end) but not sure if the others are obvious (apart from the ignition line).

Some help with diagnosis is sought; unhelpful replies are just that.

 

[45yearsagasman]

Sense of humour bypass?

 

[PlumbGas]

Yes, very good, folks, but I thought this was a DIY support forum, not a place for taking pot shots at someone with a broken boiler in the snow.

Boy were you mistaken

 

[onlyfitidealboilers]

Have you done you basic electric checks, and resistance to earth on your wiring harness check for water on the OH stat.

 

[gasright]

You've already stated that you've " opened up the boiler" which means that you've probably had a mess around in the combustion chamber.

Do you love everyone else in your household? because your doing everything to potentially have co pumping out of your boiler and into the house.

 

[windbagUK]

Have you done you basic electric checks, and resistance to earth on your wiring harness check for water on the OH stat.

Thanks for the helpful response.
Static DC resistances (Multimeter readings) are:
L-E 4.3 MΩ
N-E 5.4 MΩ
L-N 72kΩ
which don't immediately ring alarm bells.

As for water on OH stat - if you mean external liquid, no both the Control Thermistor & Overheat thermostat are dry.
If you mean water inside, I have no reason to doubt that, as the circ system hasn't been touched since the L8 error first came up, when all was working fine.
Main (external) water pump is running smooth & quiet within 3 fused supply (separate test).

Could I run the system up with just the mains input to the PCB, with all the other plugs (fan, gas valve etc) not connected?

If so, is the mains supplied by the rear/right 4-way connector?

 

[nickso]

No, mains input is obvious if you follow it from the plug under the boiler.

Before you do anything why not remove each plug from the PCB and test for a short? A wiring diagram is not hard to come by.