Baxi Combi 105E

[MZR]

Hi all,

i have a random problem with the above boiler !

the heating works fine until you turn the hot water on, then you can hear it switch back to the heating and the radiator led is alight but i the burner wont light until you reset the boiler, this does not happen all the time just now and again, i have also turned the hot tap back on until is fires up ,then switch it off the heating switches back on and fires up with out a reset. its an intermittent problem well every day i have to mess about.

would this be a faulty diverter ?

thanks for you input guys

 

[Shefflad]

Sounds similar to what was happening with my other half's 105. The pin in the diverter valve was stuck open, but hers was on the heating side. With the cover off the diverter is on the left, the HW pin is at the front and the CH pin at the rear. Check they both move in and out with demand - eg front pin will move out when hot tap turned on, and recede back when tap off. CH pin will move out with call for heat, and in when demand satisfied. I freed hers off with some silicon lube and a toothbrush as it was caked in stuff.

It's possible the diverter diaphragm has gone though.

 

[desrob]

Hi all,

i have a random problem with the above boiler !

the heating works fine until you turn the hot water on, then you can hear it switch back to the heating and the radiator led is alight but i the burner wont light until you reset the boiler, this does not happen all the time just now and again, i have also turned the hot tap back on until is fires up ,then switch it off the heating switches back on and fires up with out a reset. its an intermittent problem well every day i have to mess about.

would this be a faulty diverter ?

thanks for you input guys[/QUOTEyour gas safe engineer will tell you all you need to know and for a price fix it for you.

 

[MZR]

Hi all,

i have a random problem with the above boiler !

the heating works fine until you turn the hot water on, then you can hear it switch back to the heating and the radiator led is alight but i the burner wont light until you reset the boiler, this does not happen all the time just now and again, i have also turned the hot tap back on until is fires up ,then switch it off the heating switches back on and fires up with out a reset. its an intermittent problem well every day i have to mess about.

would this be a faulty diverter ?

thanks for you input guys[/QUOTEyour gas safe engineer will tell you all you need to know and for a price fix it for you.

i will be fixing it myself so no engineer will be needed just need to find the cause

 

[sparra1100]

i will be fixing it myself so no engineer will be needed just need to find the cause

an if your not a plumber or gas safe and never done one before lets hope ye dont flood the house

 

[diamondgas]

105E has a cycle time delay and may not relight for 10 mins when switching back to heating 🙂

If your hot water is fine and heating is fine then the diverter is working as it should .. Its mechanical spring return to heating!

There are several switches that can be tempremental as well as sensors that may be out of range ....

Seen so many parts swapers on this site which is soooo funny to read :lol: They'll spend hundreds on parts rather than pay a lot less to get the problem solved... If you feel confident in tracing the fault yourself then fare enough.... Good luck. 🙂

 

[Puddle]

Take it the reset light does not come on,do not think it is the diverter valve sticking as if so this would not be corrected by just moving switch over to reset,this seems to point to electrical side,as said there is a time delay,maybe this is faulty,intermittent faults can be a bummer to sort out ,no reason why but I would maybe replace heating thermistor and see if any change,also clean out pump flow switch and grease spindle,as it could be ,that you are stop /starting pump during reset,having said that,it could also jolt diverter valve if sticking,never had that though
Other thoughts involve removing combustion chamber and would require a gsr operative am afraid to say

imho

 

[MZR]

an if your not a plumber or gas safe and never done one before lets hope ye dont flood the house

Luck would have it that i am a plumber and that i will be gsr when i have taken my ACS after the new year, so being qualified is not going to be a problem BUT experience in boiler repairs is something i don't have but im sure if i keep reading the posts like these and get some good problems solved under my belt then the experience will come.

i will try the things that you guys have suggested, i think a service would be a start also as it not had one in years LOL

if you guys could suggest any other solutions also

thank you all for your input so far

 

[diamondgas]

Experience gained from working on your own appliance is worth while regardless of the cost. However the training and accreditation would be best undertaken before messing with anything gas related IMO!

Do you possess a multimeter and know how to use it, interpret the readings ohms AC/DC volts etc.?

 

[MZR]

Experience gained from working on your own appliance is worth while regardless of the cost. However the training and accreditation would be best undertaken before messing with anything gas related IMO!

Do you possess a multimeter and know how to use it, interpret the readings ohms AC/DC volts etc.?

as part of the acs training that i have been given they showed us how to use a muliti meter i do have a basic one but would like to get a decent one for the future also.

 

[diamondgas]

You need one if you're serious about getting into repairs... To be honest though, learn the expected sequence of events, that way if something goes wrong then you're aware of where in the sequence it has failed 🙂

Back to your fault though ... it the radiator light flashing or on permanent? Do you have to physically re-set by turning the switch B4 the heating will come back on?

 

[diamondgas]

Just re-read the your original post MZR .... I'd take puddle's advice and check out the pump flow detection 🙂

 

[MZR]

Just re-read the your original post MZR .... I'd take puddle's advice and check out the pump flow detection 🙂

ok i will check that out thx

can you guys advise on which multi meter would be best for the jobs ahead ???

 

[diamondgas]

wouldn't know new makes MZR ... I have a Fluke which is easily 15yrs plus 🙂

 

[dancinplumba]

fluke imo 🙂

 

[GrahamM]

Fluke all the way. The 116 is just about as good quality and as simple to use as it gets for the money.
Had it for years. Left in van at way bellow zero degrees every winter, used and abused, and still a faultless bit of kit.

 

[jtsplumbing]

Good luck with ACS ! but this is no guarantee that Gas Safe will let you on register, you will need proof of working with gas, I think it`s 2 years, if not got this then dont waste your money applying, they will keep this fee

 

[casaco]

Before you spend large amounts of money, check the pin comes out fully on the DHW pressure differential valve, sometimes when the diaphragm is either pinholed or just stretched, the boiler can be a bit hit and miss for a while. Also if you know how, check that the micro-switch is actually working, you need to pull the pug out of the pcb, (with power off) turn a tap on and see if you have continuity across the two wires.

 

[MZR]

dont know if its worth mentioning, TODAY i went to see if the heating had come on as it was a bit cold, i found the boiler running with the hot water led on (not flashing) but the burner light was not on and i had not used any water for at least 2 hours ?, i sat and waited for about 10 mins and the boiler was running for the whole 10mins with the DHW led light but nothing else, i switched the hot water tap on then off and then the heating came on with burner light.

the heating was timed to come on but it didnt due to the hot water led, and the preheat is off, so there was not reason for the boiler to be running the DHW ?

it sounds to me like its not switching back correctly and this is not igniting the burner ? <---thats my random guess LOL

 

[casaco]

Is your boiler the plain 105E or the 105E instant, what is the GC number.
If your DHW LED is on then you have a hot water demand, either the pin is stuck out or the micro-switch is faulty. Turn the dial on hot water to zero, does the boiler switch back to heating?

 

[MZR]

ITS THE 105E INSTANT,i will try that when it plays up again

 

[Puddle]

That makes it a big difference ,it's a different boiler inside !!

:6:

 

[MZR]

sorry guys i only realized when i read another post about the pre heat. lesson learnt (always post correct make and model)