Ideal Isar HE35 Leaks after PCB Replacement

My Ideal Isar HE35 boiler recently broke down, no lights/display, no noise no response at all when switched on. I called a guy out to fix it, who installed a new PCB. The transformer on the old PCB had burned out. There's no other visible fault on the PCB, or sign of water getting into it. The boiler then started up, giving fault code H 5 . This code wasn't in the manual, so he spent quite a while examining different bits of the boiler and scratching his head. I Googled the fault code, it turned out he hadn't set the jumper on the PCB which specifies the boiler model. After setting the jumper heat and hot water worked. after he left I bled the radiators (including 1 that I had recently re-fitted after wallpapering), pressurised the system up to 1.5 bar (installation pressure is 1-2 bar) then went out, leaving the heating running to warm up my cold house.

I came back 1 hour later, to find lots of water coming out of the bottom of the boiler. I turned the power off at the wall and called the guy back. He returned the next day, and discovered that water was leaking from the automatic air vent in the heat exchanger. He says he can't fix it, and suggests I call Ideal to sort it. He insists that he couldn't have caused the leak, although he can't explain what's caused it.

Question is:

Could he have damaged the valve looking for the cause of the fault code?

Could the freezing cold weather have caused the problem,perhaps the condensate drain to an outside pipe freezing up?

Could it be some other underlying fault that's been triggered when I pressurised the system after bleeding?

The boiler's about 5 years old, and has never been serviced.


All thoughts and ideas appreciated.

Could have been the draining and refilling causing float to fall down and a bit of dirt stopping it sealing when topped back up. Relatively easy to change if you have the right set of grips. About 20 mins tops. Sometimes easier if you remove burner to get in at it.

The AAV has probably got a bit of dirt in after the pressure loss/repressurisation.
Why cant he fix it? its an easy job,takes about 30 mins,to fit a new AAV.

a common fault.

usually the rubber o-ring is too hard to reseal after its unseated or dirt gets trapped. not difficult to replace in most case although i had one that was stuck fast.

Garfeild said:

Why cant he fix it? its an easy job,takes about 30 mins,to fit a new AAV.

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Probably because he's half clueless. The PCB came with a leaflet explaining the jumper settings, which he only bothered to read after I told him what the fault code meant.

Sounds like you want to blame "the guy" I am sure he would not have left a problem on purpose to come back in his own time and not gat paid! There's plenty out there who would not have returned.
What are the reasons for you not having it serviced are you saving up for a new boiler

barryauid said:

Sounds like you want to blame "the guy" I am sure he would not have left a problem on purpose to come back in his own time and not gat paid! There's plenty out there who would not have returned.
What are the reasons for you not having it serviced are you saving up for a new boiler

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I'm not necessarily trying to blame him, but when I have to explain to a supposedly expert professional how to fit a part correctly it doesn't do much to build my trust in him. I want to establish whether he is indeed at fault, or whether it's just coincidence. From the answers above, it looks like it may be unfortunate coincidence. I currently do PC repairs, and I've occasionally had those unfortunate concidences happen.

As far as servicing goes, I'm not really used to the idea of servicing heating appliances. My old boiler was a very simple 1960's vintage, oil-fired Husquvarna furnace. It didn't need any maintenance beyond the chimney being swept every couple of years. I should really get it serviced.

Ideal Isar/Icos are one of the few boilers that MUST be serviced correctly every year.

80% of faults are caused by lack of service.

Surely ALL boilers should be serviced correctly?

Yes I agree, but most others will not suffer from a blocked condensate trap/sump so quickly as these.

in fairness to the installer if he isn't familiar with these crates then it is easy to miss the jumpers in the control panel rather than the PCB itself, have done it myself once this is the main cause of H5 code appearing.

the other regular problem is the grey sludge that builds up in the condense trap.

the fittng of the PCB and the water loss problem are NOT connected and it definately the de-pressurisation that has caused said leak.

the installer would have seen the leak when changing the board had it been there when he changed it over

did he drain the system to change a pcb?????
if so i wouldn't recommend him doing anymore work for you
what number comes up on the display after you turn boiler on/off,you need to see a 6 if hes put the jumpers in correctly

sorry

just read it properly but it was you who has damaged the aav,when you removed the radiator

A long story drastically shortened and kept to the point

I just had a mare with one on Christmas eve. I fixed the leak which was intermittent from an o ring on the plate heat exchanger. It nipped up from underneath quite easily with a torx tool. Someone else meanwhile had been pulling wires off the pcb and when the display was lost I knew that the water had probably killed it.

Strike Team said:

I'm not necessarily trying to blame him, but when I have to explain to a supposedly expert professional how to fit a part correctly it doesn't do much to build my trust in him.

As far as servicing goes, I'm not really used to the idea of servicing heating appliances.

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I am sorry to have to say this but the reality is that most independents are barely adequate! Most install boilers but dont do many repairs because thats less well paid and/or they dont have the knowledge/experience.

A manufacturer's engineer is always better because they only deal with a limited range of boilers and have dealt with the same fault before so know what to do.

I am still suspicious because many PCB failures with overheated transformers are caused by water leaking from the AAV onto the display PCB/interface card. It may well have been leaking before.

Anyone familiar with your model will know about the leaking AAV and how to see if its leaked to cause he fault.

Even if it has leaked the cap can be closed as a temporary bodge fix.

Anyone who replaces the PCB without cleaning/inspecting the sump on your model is a nupty!

I am sorry to say that you are contributing to your problems because you dont bother to get the boiler serviced by a competent engineer. A BG safety check is NOT a service however!

Tony

The PCB fault is common. However, water leak can not have been caused by your engineer. More likely due to YOU repressurising too quickly. The air seperator is a simple device that expects to cope with small amounts of occasional air to remove.

May I suggest that this boiler requires yearly service due to known issues.