Heatslave 12/14 morning start up, lock out problem?

31 Mar 2010
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United Kingdom
I would appreciate someones advice here if possible? My heatslave 12/14 oil boiler has recently started to go to lockout first thing in the morning. :cry: It then starts when the lockout switch is pressed and runs no problem the rest of the day for both CH and HW when left on. It would seem however if left off for a period of approx. 6+ hours it is reluctant to start up straight away, as mentioned with the lockout switch pressed. Could it be anything to do with a lower oil pump pressure on the very first start up but then the pressure has built enough to then work ok when the reset button is pressed. I have noticed during the period when it hasn't started, fan motor working fine and the oil mist is coming out of the flue so oil is present at this time.
I look forward to any words of wisdom.
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I doubt its anything do to with your suggestion.

The obvious question is when was it last serviced?

Do you know if its actually sparking when it fails to light?

I might suspect the mixture is wrong.

Thank you for the very quick reponse. It was last serviced approx. 14 months ago although I did fit a new nozzle a month ago. I do not actually know if it is sparking on initial start, what would you suspect if it did then spark when the reset button is pressed? Would the mixture change between the initial start and the reset button being pressed?
I would want to know if it is sparking !

Thats crucial to my next suggestion.

I have presumed you know that it does not actually fire up as opposed to firing up but locking out because the flame is not detected.

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I will have to look at this again tomorrow morning at the initial spark, right now its working ok.
I am slighlty confused by your term "firing up but locking out because the flame is not detected", which I am reading as sparking, but not igniting? Excuse my ignorance of your meaning here, my logic was was it's not ignited so it's not fired up.

If your 12/14 has a balanced flue, then leave the burner cover off for a while to see if it behaves itself.
Withdraw the photocell for a clean - its worth having a replacement in stock.
When you replaced the nozzle, did you upset the electrode position at all?
I think your burner will be an Inter B9A with a Danfoss .50 60 deg nozzle - and the pump pressure needs to be 100 psi.
John :)
Thank you both Tony and John for your input.
I monitored the morning start up and would advise my observations. The burner on start up immediately sparked and flamed, I believe I now understand what you meant Tony ref the comment on flame not detected. At that point I turned it off and then when I turned it back on a couple of minutes later, it went to lock out after about 5 seconds. This repeated a couple of more times before it started and then it has run all day. It does seem like the sequence after the reset button is pressed sounds slightly different i.e. the motor and pump are going and the spark and ignition occurs after 5-6 seconds rather than that initial immediate sounds of spark and burner going.
John it is a conventional flue appliance and so there is no burner cover, I checked the electrode position and there was no problem there, and the spec for the burner and nozzle are as you have stated. I have ordered a spare photocell.
and of course ...It never rains but it pours! :cry: This evening the missus pointed out there was a slightly higher pitched sound coming from the cupboard! I suspect the motor and touching both the oil pump and motor they were both very hot to touch.
Any further comments you may have would be appreciated.
When you changed the nozzle it is possible the old nozzle was left in from a previous service. In other words it might have been worn and the oil/air settings adjusted at the last service interval to compensate.

Most of us in the trade would check the oil pump pressure when changing the nozzle and then carry out a combustion analyser or smoke test.

Just changing the nozzle is asking for trouble without making the other checks.
Thank you for the advice Simon. I know that the service guy we have used has always replaced and invoiced for a new nozzle so I do not suspect he adjusted and left an old one in.

I suspect its the capacitor[i think thats how you spell it], if these are not strong enough to kick motor in then it goes to lockout. Once you depress the lockout button it re-enegieses the capacitor therefore the boiler continues to function

Well I did fit a new photocell, about 11:30pm one evening and hey presto the next morning at 7am on comes the boiler straight away :D ....a very happy day!
Then the next morning....... back to square one, and ever since lockout two or three times before she goes! So I can only presume it was a little bit less time that first occasion when I tried it, as the boiler usually goes off at about 10pm.
The better news is the higher pitched boiler noise has disappeared!
I will consider the capacitor change.
smiffy bear
Smiffy, its time to test that motor on the bench.
Test it connected to the mains with the capacitor attached.
It should start to spin every time you switch it on. Test it 20 times or so, with a few seconds interval before each switch on.
If at any time it doesn't spin up, or the shaft just oscillates slightly, the cap or motor are goosed.
John :)
Thank you for the advice John. Typically because I have been able to restart it by pressing the reset button a couple of times and as the sun has been out:cool: I have yet to revisit the test on the motor! I hopefully will get to it at the weekend so will let you know.

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