baxi combi 80 eco firing problem

by **willsy369** » Tue Dec 30, 2008 5:19 pm

Hi all,

I have a Baxi combi 80 ECO, fires up on heating and on water, but on heating goes out after random seconds or mins running, on hot water it goes on then off and so on. (similar to ignition board faults on vokera boilers, but these do not have them on the gas valve hence i thought PCB) changed PCB and micro switch but no change in fault, and now thinking about the gas valve or fan?? checked voltage and all ok, seams to click to want to come on but only does for short periods and not constantly for hot water. 240v goes into the board fine and gas pressure is correct yet the thing keeps going on and off for central heating and on and off for hot water causing a hot bit and then cold etc!

many thanks in advance for any suggestions, ive looked on the fault finding guide seams to point to pcb or gas valve but surly the valve is working if it opens in the first place? unless weak solonoids but the voltage is what closes it as i checked and the voltage goes and it closes. help me please!

Sponsor

by **gasmick** » Fri Jan 02, 2009 10:48 pm

hi it sounds like you need to get the A P S switch checked out before you go any further, this is not a job for diy, as you will also have to check out the ventura on the fan to see if its not partially blocked, as that will cause the problem as well, and also the tubes to the air pressure switch need to be checked out for any holes , so get your local R G I to check it out for you

by **htg engineer** » Mon Jan 05, 2009 7:23 pm

Check HW and CH sensors.

htg

by **delboy786** » Tue Jan 06, 2009 5:11 pm

Hi there,

I would be tempted to try the temp sensor.

Best wishes
Al

[quote="willsy369"]Hi all,

I have a Baxi combi 80 ECO, fires up on heating and on water, but on heating goes out after random seconds or mins running, on hot water it goes on then off and so on. (similar to ignition board faults on vokera boilers, but these do not have them on the gas valve hence i thought PCB) changed PCB and micro switch but no change in fault, and now thinking about the gas valve or fan?? checked voltage and all ok, seams to click to want to come on but only does for short periods and not constantly for hot water. 240v goes into the board fine and gas pressure is correct yet the thing keeps going on and off for central heating and on and off for hot water causing a hot bit and then cold etc!

many thanks in advance for any suggestions, ive looked on the fault finding guide seams to point to pcb or gas valve but surly the valve is working if it opens in the first place? unless weak solonoids but the voltage is what closes it as i checked and the voltage goes and it closes. help me please![/quote]

by **TheDoctor5** » Fri Jan 30, 2009 11:17 am

If you type the key words of your question into our search box to the left of the site you may find the answer is already posted or is in the DIY projects section of the website. Every post goes through a monitoring process and using the search box may speed up your answer.

by **shambler** » Wed Feb 25, 2009 5:47 am

Did you ever find the soultion to this problem?, my Baxi eco 80 is doing EXACTLY the same thing. :cry:

by **gasmick** » Wed Feb 25, 2009 9:45 pm

Hi its a problem with many forums you give advice as an engineer to a problem posted as lots of others do the same, but the original poster never seems to finnish off their posting with a problem solved post ???
at least we as engineers would know if our solution worked for them
and thanks would be nice, makes you wonder whether its all worth the effort in replying to peoples problems

mick

by **shambler** » Fri Feb 27, 2009 5:47 am

[quote="gasmick"]Hi its a problem with some forums you give advice as an engineer to a problem posted as lots of others do the same, but the original poster never seems to finnish off their posting with a problem solved post ???
at least we as engineers would know if our solution worked for them
and thanks would be nice, makes you wonder whether its all worth the effort in replying to peoples problems

mick[/quote]

Hi Mick, I agree with you since I have seen many forums where people with this problem have never come back with the actual reason so nobody learns anything.

I have exhausted my fault finding abilities on this boiler ( I'm a electrical engineer so I'm not going to start taking gas fittings apart ) I've checked the temp stat which seems OK (11KOhm cold 3KOhm hot) and all the switches are being actuated and are working.

I have cleaned the system with sentinel X400 and drained it out...water looked pretty clean so I don't think it is a blocked heat exchanger as suggested on another site.

I've just got the APS to check then I'll be calling in the professionals.

Rest assured I will post an answer to this problem after I have shelled out some readies :shock:

by **shambler** » Tue Mar 03, 2009 9:33 am

Update.

It is looking like its the temperature sensor, although it was reading fine when I checked it, it has now gone open cct.

Should get a replacement in a day or two, will let you know the outcome.

by **shambler** » Thu Mar 05, 2009 9:49 am

Temperature sensor changed, normal service is resumed :wink:

by **carraramario** » Sun Nov 06, 2011 9:09 pm

Hi there. i am facing the same problems and I will try to replace the temp sensor. i will keep you posted.

by **Tinkabelle** » Mon Nov 21, 2011 10:58 am

Hi, this is happening to me too.. I know I can buy a sensor online, but how do I go about fitting it? I can't see any instructions online