Where are you for starters, have you tried another oil engineer that knows what he's doing.

What is locking out the burner or the boiler.

Does the boiler run for a while before locking out, if so how long does the rads etc get hot.

What does the engineer do when he give it a service, it takes over an hour to do properly nearer two.

Important bits are to clean the combustion head, non return valve, and the baffles.

see below.

14.1 The following should be carried out at least once per year
for 28 second Kerosene and twice per year for 35 second Gas
Oil, to ensure efficient, trouble free operation.
1. Carry out a pre-service check noting any operational faults.
2. Check and clean the burner.
3. On the CF model check and clean the air intake grille located
in the boiler room.
4. On the RS balanced flue model check and clean the air intake
ducts at the rear and underneath the boiler and the air intake
grille at the end of the terminal.
5. Check and clean the baffle retainer (20/25, 26/32, 32/50
and 50/70 models).

7. Check and clean the baffles.
8. Check and clean the heat exchanger surface.
9. Check the heat shield (20/25, 26/32, 32/50 and 50/70
models).
10. Check the combustion chamber base insulation board.
11. Check that the flue system is unobstructed and clean as
necessary.
12. If the appliance has been installed in a compartment check
that the ventilation areas are clear.
13. Clean all oil filters.
Some of the servicing points are covered more fully in the
following instructions:-
14.2 Pre-Service Check
1. Remove the cabinet front and top panels as described in
section 5 .
2. On the RS balanced flue model remove the burner box cover
as described in Section 5.5.
3. Operate the appliance and system, noting any faults which
may need to be corrected during the service.
14.3 Cleaning the Burner
IMPORTANT: Disconnect the electrical supply at the mains
before commencing any servicing. Turn off the oil at the service
cock.
1. Remove the burner.
(a) Isolate the oil supply at both the oil tank and the isolating
valve situated above the burner on the right-hand side. (See
Figs. 2 and 3).
(b) On the RS balanced flue model remove the burner box cover
by pulling forwards to release the ball studs. This will be found
easier by pulling on one side of the handle first to release two of
the ball studs and then repeating on the other side. Take care
not to pivot the remaining two ball studs too far around as this
will cause damage to the spring clips.
(c) Disconnect the electrical lead from the control box by
depressing the two locking ears on the plug and pulling
downwards.

Hi,

Thanks for such a comprehensive response.

I am based in North Wiltshire, and had extreme difficulty finding someone who could look at the boiler.  Firstly the guy that originally installed it was no longer qualified to work on them anymore, the second guy was an installer only and did not do repairs (but did show us the reset button given that we had been without heat and hot water for a few days mid-winter and the 3rd guy was all I could find who would service/repair - who has been out 3 times now to service.

I am not sure if it is the boiler or burner locking out, but I have to take the front panel off, and then pull the bottom metalwork off and press the reset button on the right hand side of this to get it working again.

With regards operation, it will work quite happily on a low setting for a couple of weeks, and then go through a phase of locking out every day or more for a week, and will then run for a couple of weeks again and then we start again.  Central heating and water work perfectly, either alone or combined, and there appears to be no pattern as to when it will fail - so essentially totally unreliable.  If I turn the temp on the boiler up, it will fail in 20 mins or so guaranteed.

Any assistance most welcome

The engineer that comes out typically spends between 40 and 60 mins doing the annual service if that helps any.

Thanks again.
red-robbo  

Which model do you have.

sorry missed your second post.  I don't know if it is a CF or RS? - all that is on the outside is Worcester Danesmore 20/25 - it does not have a built in timer etc, that is a separate Potterton unit attached to a Honeywell FrostStat.

cheers
red-robbo

I have the same oil boiler and mine is going into lockout every now and then ?

Boiler man came today, he thinks its the EB1 transformer, new one fitted, lets wait and see.

We had a similar situation happen last year, ours turned out to be the motor was on the way out, so every now and then we weren't getting enough oil pressure for a stable burn.

The engineer showed me the old motor and you could actually feel that the bearings had gone.

Paul

Yes you need to bleed the air out of the line, or you'll burn the pump out.

Turn the valve off, and disconnect the flexible, stick the end in a vessel and draw some oil through by opening the valve, reconnect flexible and test.