On Mon, 3 Dec 2012 12:53:53 -0800 (PST), Chris Holmes
wrote:
On Dec 3, 7:15*pm, MM wrote:
On Mon, 03 Dec 2012 18:37:08 +0000 (GMT), "Dave Liquorice"
wrote:
On Mon, 03 Dec 2012 18:04:09 +0000, MM wrote:
When my boiler locks out, there is no indication whatsoever of any
prior activity. The Danfoss "calls for heat", some seconds elapse, the
LED comes on. Finito.
Does the lockout LED come on at the same time as the power indicator or
does the power indicator lead by some seconds?
Ah, now that I cannot say! It is something that has been bugging me,
too.
You see, the Danfoss is inside the house and the boiler is outside on
the garage wall. I cannot observe both switching on the manyal
override button on the Danfoss whilst simultaneously watching the
boiler control box LED.
Even if I let the heating come on by a timed event and am waiting
outside the boiler a minute or two earlier, I cannot watch both the
LED on the Danfoss AND the LED on the control box!
I even thought of setting up my web cam, but that would entail major
upheaval throughout the house. Not saying I wouldn't do it, though...
I actually thought of mirrors. When my previous car was due its MOT I
checked the stop lights by means of a mirror mounted temporarily on my
standard lamp!
If you have any ideas how this may be achieved, feel free to suggest
anything!
Now I'll try and draw you a picture of the layout:http://www.littletyke.myzen.co.uk/house.jpg
So... in order to run a test "call for heating" I remove the cover
from the boiler housing (from the garden path along the side of the
garage). Then I go back inside and press the required manual override
button on the Danfoss (either heating or hot water). Then I, as
quickly as possible, race back to the boiler (several metres away and
round a 90 deg corner) and observe what happens, if necessary pressing
the reset button if lockout occurs.
The toilet has an opening window near the boiler. Sometimes, in order
to check whether the boiler has come on, I open the toilet window and
listen for (a) the fan and (b) the burner.
But I can't see any way to press the button on the Danfoss AND watch
the control box. I can't ask the neighbour to press the Danfoss button
for me while I watch the boiler because he's waiting for a heart valve
replacement, is quite poorly and never goes out in the cold weather
which apparently hits him like a train. And if I allow the Danfoss to
trigger on the timer, then I cannot see the exact second it actually
sends its "call for heat" message to the boiler.
I need some ingenious method like my mirror on a stick for checking
the stop lights!
MM
Here's a thought..........
What if th lockout is occurring not as part of the startup procedure,
but at the end
Of the previous shutdown?
This COULD POSSIBLY be caused by flue gasses or unspent oil hanging
Around (due to them not having been got rid of by the fan "running on"
After the firing (because it has no mains as (I think) there is no
perms ant live.
As I stated earlier IANAHE and I don't know if it could work this way,
but it might.
I don't know enough about boilers to be able to tell, although your
point sounds perfectly reasonable. But the thing is, the moment that
the Danfoss switches off, so does the boiler, including the control
box LED. I know this because several times I've checked the boiler
BEFORE switching on the Danfoss (or allowing it to trigger by timer)
and the control box LED is always off to begin with.
Here may be one new clue: For the past few weeks I have programmed the
"call for heat" cycles as follows (on the Danfoss):
Mon through Sun, heating only (I switch on the boiler for hot water
only when needed, not on the timer):
ON at 04:30 OFF at 05:00
ON at 17:00 OFF at 17:00 (i.e. NO call for heat, see note below)
ON at 23:00 OFF at 23:30
This was purely for frost protection purposes so that it didn't get
too cold in the loft (I've since opened the loft hatch by 45 degrees
as well).
However, since the weather turned colder, I've revised the programme
as follows:
ON at 04:30 OFF at 07:30
ON at 16:00 OFF at 17:30
ON at 21:00 OFF at 22:30
Note on the Danfoss: If the ON and OFF times are the same, this
effectively cancels that event.
Now, since I went to the longer ON times I've noticed that the boiler
also locks out sometimes during the cycle. So, for instance, it will
come on at 04:30, rads get nice and hot, then I happen to be passing
one of the rads and feel it and it's going cold again. This has
happened at random times. On checking the control box LED, it's ON
constant, ie. locked out. I press the reset button once more and the
boiler comes on and usually finishes its cycle, e.g. right up until
07:30.
On one occasion the lockout happened after about 30 minutes into the
cycle. Another time the boiler ran for about 1.5 hours and then
lockout occurred.
Usually, however, once the boiler has started, it will run to the end
of the desired period.
When I say "run", I mean that its typical behaviour is to come on,
burn for about 15 minutes, then switch off. It then waits for around 4
minutes and then comes back on for only a few minutes, provided the
cycle specified by the Danfoss programme is still active. The boiler
will thus switch itself ON and OFF numerous times during a long "call
for heat" cycle.
If any part of the above isn't clear, let me know!
Thanks for your response BTW.
MM