ISAR HE24 COMBUSTION CO READINGS VERY HIGH !!

[mmalone]

Folks, went to an ISAR HE24 today and after fitting the new pcb telganed it, the CO reading wnt skyhigh, removed the cover and reading went right down, still around the 0.0010 mark but well passable..
checked everything, all seals and visually the flue looked fine, Ideal suggested replacing but not sure this will cure the problem, the mix on the gas valve is preset and 20mb at inlet !

just wondering if anyone has come across many like this and whats recomended..

Ive ordered the flue purely because the reading drop so low when the cover is off. any other thoughts people ??

 

[Agile]

Sounds like a flue seal letting POC pass to the inlet duct !!!

Tony

 

[gas4you]

Check the insulation in the burner/heat exchanger has not fallen/ obstructing the burner, even though it does fire down. 0.0010 is the co/co2 ratio reading not the co reading What was the co2 reading also, usually between 8.6-9.1%, co usually reads around 100ppm.

 

[mmalone]

Check the insulation in the burner/heat exchanger has not fallen/ obstructing the burner, even though it does fire down. 0.0010 is the co/co2 ratio reading not the co reading What was the co2 reading also, usually between 8.6-9.1%, co usually reads around 100ppm.

yeah its the ratio..

with cover off it sits around 9.9% about 120 ppm slightly higher than normal
with cover on ppm goes off the scale over 4000ppm

is it possible for the insulation to fall off even if the burner or heat engine has not been disturbed recently ??

 

[gas4you]

I have never had one higher than 9.1% before or after a service and I've fitted and serviced loads.

Can't guarantee insulation is the fault, but has been known to fall out an burn. One extreme case a mate had had to have a whole new heat exchanger because of it. Outside possibility that the burner is knackered as well.

Can't think what else could cause it though if flue is clear. If seals had gone I would expect the boiler to keep choking its self when sucking in co it was producing.

At 4000ppm CO I would have turned it off

Edit, no offence to you and I'm clutching at straws, but some silly buggar hasn't hooked it up to LPG by any chance

 

[mmalone]

I have never had one higher than 9.1% before or after a service and I've fitted and serviced loads.

Can't guarantee insulation is the fault, but has been known to fall out an burn. One extreme case a mate had had to have a whole new heat exchanger because of it. Outside possibility that the burner is knackered as well.

Can't think what else could cause it though if flue is clear. If seals had gone I would expect the boiler to keep choking its self when sucking in co it was producing.

At 4000ppm CO I would have turned it off

Edit, no offence to you and I'm clutching at straws, but some silly buggar hasn't hooked it up to LPG by any chance

its off mate !! and no lpg !!

it wasnt my job, just went to help one of our younger engineers but original fault was LF and spent so long sorting this as it already had a stack of parts fitted, pcb, divertor, both electrodes , sensors !!!!!!!!!!
never had the time to go into the guts off it. ended up putting original pcb back in and the LF fault dissapeared for now anyway..

makes me think though the LF fault islinked to high combustion, boiler original falt would fire and run for 30-40 seconds then cut out, customer would keep resetting and eventually after 3 or 4 resets it would run for a couple of hours before faulting again..

ordered flue but will advise to check the the burner and combustion panels on next visit on thursday..

thanks for the advise !! these things really are heaps of **** !!

 

[gas4you]

Everytime I service one as per Ideals factory instructions, 3 kettles of boiling water through the heat exchanger, as well as stripping outher parts out to clean, I usually get the LF fault, flame rectification, this is due to the rectification electrode remaining damp, even after drying it off. Sometimes I even get the HF code as soon as it is switched on. After about 5 mins of trying to fire and resetting it clears itself with no more bother.

Worst one I had took 30 mins approx, with me stripping it all out again and double checking electrodes etc. In the end I carefully 'emery clothed' the rectification electrode and it worked

The old M30100 Isars were the worst.

As you say, what a load of c**p

 

[mmalone]

Everytime I service one as per Ideals factory instructions, 3 kettles of boiling water through the heat exchanger, as well as stripping outher parts out to clean, I usually get the LF fault, flame rectification, this is due to the rectification electrode remaining damp, even after drying it off. Sometimes I even get the HF code as soon as it is switched on. After about 5 mins of trying to fire and resetting it clears itself with no more bother.

Worst one I had took 30 mins approx, with me stripping it all out again and double checking electrodes etc. In the end I carefully 'emery clothed' the rectification electrode and it worked

The old M30100 Isars were the worst.

As you say, what a load of c**p

will keep you updated on outcome mate once I speak to the engineer..

its hard to understand why the same manufacturers of the trusty classic got this heap of junk so wrong !!

 

[ACOperson]

Don't see what was so good about the classic mate. New fan every 5 years on the FF and a long and tiresome thermocouple change on PP model. Why the hell put the thermocouple at the back?!

IMO Ideal's only good boilers are the 18yrs + floorstanders (Mexico, E Type...)

 

[simond]

Agreed, Mr ACOperson.

 

[gas4you]

And the pain the the a**e screw at the back under the flue holding the fan assembly down. Can't always get the sliding flue bit out easily

 

[DP]

Gas4you, try following link spanner for the difficult screw http://rswww.com/cgi-bin/bv/rswww/s...cgaddlegljfdjcefeceeldgkidhgh.0&cacheID=ukie.

As for the flue, can be difficult but a short screwdriver through the holes in inner tube does help removal.

 

[gas4you]

Thanks DP I use a spanner on the newer models that allow it, but the older ones are just a phillips head.

Tried the link, but says session timed out.

 

[mmalone]

Don't see what was so good about the classic mate. New fan every 5 years on the FF and a long and tiresome thermocouple change on PP model. Why the hell put the thermocouple at the back?!

IMO Ideal's only good boilers are the 18yrs + floorstanders (Mexico, E Type...)

still a very reliable boiler, with exception to the fan issue they still top most boilers on the market.

 

[mmalone]

guys just to update you all on this !

Gas4u was bang on with the problem, but due to the customer constantly resetting the cumbustion panel was blown off with the explosive ignition and burnt right through to the back of the thing and cracked the back casing on the boiler, new boiler required...

very scary to look at apparently, this thing is only 2/3 year old and has been 1 problem after another but to burn right through and crack the back of the boiler is unbelievable.. very scary, so glad it was turned off as this could have been disasterous !!!

gas4u, cheers for the advise our engineer went straight to this and will be well and truly noted for future isses with LF fault / explosive ignition and high combustion readings..