Intermittent boiler problems

Hi all,

I am having serious problems with a wall mounted bolider in a fairly new apartment. It is an intermittent fault, in as much as the heat or hot water will be on and will suddenly just stop, with the boiler flashing a fault. One red light flashing in between two green lights.

I have tried the builder but he is not returning calls. I have tried the boiler manufacturer who sent out a plumber, ESB and Bord Gais. Everyone is very helpful but they all admit they don't know what is wrong. They say the fact that it is intermittent means they can't figure it out, it could be many things.

The pump was replaced but that didn't work and the pressure seems to be okay also. Has anyone out there ever come across this or can you point me in the right direction. This is costing me money that I just can't afford and its still not getting fixed.

Cheers,

Stevo32

Have you checked your room theromstats. What is the make/model of the boiler. Do you know if any of your neighbours have been experiencing any similar problems?

ya, Make and model are a most .

Thanks for the speedy reply. The boiler is a Biasi M90D.24SR. The plumber checked the thermostat, which is in the hall and siad it was fine. Should I just go ahead and ask them to change the motherboard (as was already suggested by one with no guarantee)? Should I ring back the manufacturer and ask them to send someone different. The guy they sent me was great but he basically said it could be anything, like a nail in the pipe but surely he should be able to check that out.

Also the lights are flashing green, a static red and the third does not come on. According to the manual that means faulty primary circuit, absense of flow or water but this didn't seem to help the plumber.

Any further advice would be gratefully received lads.

Stevo

How new is the system?

When it does run, do all rads get hot?

Hey,

Rads lovely and hot until the fault flashes and then they cool immediately. It's hard to pin it down to a time but between 8 and 10pm seems to be worst. I have had the plumber over a few times in the afternoon and I have managed to slip out of work but it hasn't gone then.

But its also been known to go in the morning. I use the immersion for a shower now as the other isn't reliable. Do you think you know what might be wrong??

Stevo

Could be the PCB. I'll check out the manual for it later and let you know.

Why was the pump changed and who did it?

Could be a faulty flow switch or micro switch. This feels water passing through it and activates a micro switch which in turn allows the boiler to cycle normally. It it doesn't feel water flowing, it assumes the pump isn't working and won't allow boiler to operate. It would give you a similar fault code.

Still haven't looked at the manual, but will.

The plumber the boiler company sent did it and we hoped it was a quick fix. Thanks for taking the time to offer advice. At this stage I am willing to try anything. Should I change my plumber? Rang Bord Gais and the chargers are fairly steep, jumping up every 15 minutes.

Stevo

Hi, just browsing that manual, flashing light between 2 permenant on lights is not primary circuit fault, its not even listed (Prim cir fault is lh light on, mid flashing, rh off)

at this point, ur installer/serviceman should have at least wired out all external controls `(ie clock stats etc) its very easy to do. but sounds like the problem is n the boiler eitherway, starting to suspect the control pcb..

Let me ring Biasi tomorrow and get back to you

How come you have an immersion, that is a combi boiler (instant hot water) or is that side not ben plumbed in?

Hi Stevo,

Just spoke with them, and yes, they would also suspect the pcb (control board only, not the ignition board) will have a fault if it is as you say, lh solid green, rh solid green, mid flashing red, as this is not a standard pcb error code

Just a query, do you have a toaster/kettle/microwave under your boiler, smoe people like that little space for them when they are fitted in a kitchen, and the steam from any can and does effect the pcbs (some boilers more than others)

Would not, be impressed by the guy you had out originally, get an RGII registered serviceman out

Hi DGOBS,

Thanks for that. I have nothing underneath it. I have immersion as well as the boiler controlling the heat and water. I would have been lost without as its the only thing guaranteeing a hot shower in the mornings!

The guy I had out was recommended by Biasi. I think I will give them a shout tomorrow with what you have said and see where we go. Thanks for all the advice.

That fault is listed in the manual but like you say it does not seem to be anything to do with water.

Cheers

Stevo

Only problem there is they may not discuss with you, as your not RGII or Corgi registered.

As 26/07/09 it became an offence for you to try repair the boiler yourself, that carries a 15000euor or 3 year fine.

a flashing red with solid green either side is NOT indicated in the service or installation manual fault guides that I have here for that boiler.

If you have an immersion, the combi side of the boiler is not is use, as if a combi was in use, you wouldnt have a dhw cylinder let alone the immersion, as the combi system does not require you to have one.

Please email me the fault page from you manual if possible, as it would not seem to match mine!

Hi DGOBS,

Thanks for the reply. Firstly let me be clear I would never touch my boiler or even attempt to fix it. What I know about boilers you could write on a stamp. I contacted the manufacturer because the builder went out of buisness and I thought you should go to the experts. They then gave me the name of a RGII man they recommended. However he has been out a few times and its still not fixed.

I think there may be some confusion over the lights and apologies if that was from me. It is from left to right - green light flashing, red light on and nothing on the right (light off). This is on page 17 of the manual and is the eight fault down.

I really appreciate everything you have done and the advice. Believe me it has been great to have an expert opinion. I'm just not sure where to go next. Back to the manufacturers to send out someone else or just go to Bord Gais? The prices are all based on time spent with you and I would be worried that this could clock up.

Thanks again for the help and sorry for the confusion I have caused.

Stevo

Ah ok this is a different fault! It may be due to lack of flow and this is
why the last guy fitted the pump. Bet you system water is black and your
heat exchanger has sludged up causing this intermittant flow switch issue
you may need a new heatexchanger and your system flushed and
cleansed to remedy the problem

this boiler is not unlike the idea mini s24 and I find them having the same
low tolerance for dirty systems

BTW Not every RGI can fix boilers, as in , they may lack the tech know how although I am surprised they recommended that particular one.

If the heat exchanger was partically block you nearly always hear it, the pump struggles to push the water through the heat exchanger. you also say the system is "fairly new", how new?

I would be slow to belive it has sludged up in a short period. Also you say that the rads heat up pretty quickly with good tempertures.

Time for a bet DGOBS?

My money is on the flow switch, it acts up when put under temperture over a prolonged period or could be microswitch has a loose connection or PCB but unlikely.

I'll go for the Flow switch.

Hi Stevo32, I would stick with the manufactures agent but see if there is another one you can get a second opinion from, i would stay away from Bord Gais as they can be very hit and miss with a funky fault. At this stage the engineer should have been able to rule out a boiler component, he would do this by replacing them, he may not know what's causing it but he should know what isn't, the flow switch and body should be replaced as a minimum, this is due to the design which can make them erratic and the fact that it's susceptible to sludge, if it had been replaced a good engineer could determine if sludge is a problem( Davy unfortunately i find contamination can occur after as little as 3 months especially if inhibitor has been added to a unflushed system) , the PCB would be second on my list to prove it's OK, i wouldn't think it's the PCB because it would be more erratic and your fault seems to be heat orientated, i would try turning down your boiler stat and manual opening your heating zone valve as a test to see if it has any impact on your fault, sometimes when the circuits close down and the boiler is still running the boiler can detect this as a flow problem because of the larger restriction and shut down, air in the system could be another factor if you did have a lump of air running around it could effect the flow switch but again it would be more erratic, so long story short it's wat Davy and DGOBS said, Gary

Hi Guys,

As I said earlier, have had issue with the Ideal Mini s24 in the past (practically the same boiler!) and you will se the pin of the flowswitch kick out when the pump kicks on, but the slowly edge back in, to the point where its hit and miss if the flowswitch makes.

These can be taken apart and the venturi ways around the diaphram cleaned, but have found with this particular boiler this repair last a very short time, and it's usually a dirty sludged system and the heatexchanger is partially blocked or restricted, not to the point as you say Davy where kettling can be heard, but enough to effect the operation of the flow switch (not all sludged boilers kettle!)

Simple test it, drain some sample water from the system and see how black it is, ideally the water should be clear, the black is debris held in suspension, and the will coat the inside of you appliance causing these problems

Hi guys,
Looking for some help on ideal mini s24.Boiler sparks,lights but is not rectifing.After 2-3 times it lights and stays working.Intermittent fault that is difficult to figure out.Any ideas?