Mid position valve gone u/s

[D_Hailsham]

It would happen to me

I thought I was feeling a bit cold just now, so I felt the rad - it was cold. That's nothing unusual so I asked SWMBO if she felt cold. "I've just turned the heating up", she said. So I went to the CM927 in the hall; there was a little flame showing. Checked the receiver - green light showing. Went to boiler - dead, just the pilot light.

Find meter
Mid-position valve
Turn Room stat right up - 240v on white. Good
Turn HW down - 240v on grey. Good
Check orange - nothing, zero, zilch. Not good.

Then I thought: I can't hear the motor. OK a new motor is under £20 and easy to fit. But not on my valve, which is an ACL Lifestyle 679H340-30L0 (grey cover).

I can get the cover off, it's held by a small screw at one end. But I can't see how you get at the motor - its surrounded by a metal plate on each side and a circuit board at one end; not a lot of room to manoeuvre. It also looks as if the actuator cannot be detached.

Is the motor replaceable on its own, or does it mean a complete new valve? If it is replaceable, how I get to the motor?

 

[tamz]

Bend the metal plate out the way and you will see a small star screw at the side of the motor. Take it out (don't loose it) and remove the motor (you may have to cut the wires depending on which type replacement you have. Any synchron motor will do). Fit a new motor and reinsert the screw and connect the wires back up. Bend the plate back into position and refit cover.
Job done

 

[namsag]

I am surprised with the excellent advice you give Dhailsham you are stuck with something as simple as this. Sorry if its sucking eggs but check voltage going to actual motor wires as it could be a faulty circuit board in valve in which case its a new valve

 

[D_Hailsham]

Mystery deepens

Not long after my first post the wife said: "I've just felt the rads and they are warm". Quick check - yes, the boiler was working.

Go to bed thinking that it can wait until the morning. Wake up and the house was warm. Thought I had better check in any case. All checks passed OK - HW, HW and CH, CH only

Bend the metal plate out the way and you will see a small star screw at the side of the motor. Take it out (don't loose it) and remove the motor

Removed first screw - motor still stuck; wrong screw it was the earth screw!
Moved wires aside and saw a second, smaller screw. Undid this - motor still stuck. Get mirror and torch; there was a second screw at the back!!!

I am surprised with the excellent advice you give Dhailsham you are stuck with something as simple as this.

I know, but it was late at night and the day the clocks changed.

I agree it could be a faulty micro-switch or another component on the circuit board but, as long as it carries on working, I think I will leave it alone. Changing a complete valve is better done when the heating is not required.

 

[Agile]

Its also amusing that you give so much advice on energy efficient ( and good advice too ) but you are still using an old boiler with a pilot light !

I am also surprised that you dont follow your own advice to use the scrappage scheme to get it replaced by a local gas registered installer.

Tony

 

[D_Hailsham]

Its also amusing that you give so much advice on energy efficient ( and good advice too ) but you are still using an old boiler with a pilot light !

But my advice has always been that you should not change a boiler until it has broken down and either cannot be repaired or is uneconomical to repair.

I'm still waiting for that to happen.

I am also surprised that you don't follow your own advice to use the scrappage scheme to get it replaced by a local gas registered installer.

Unfortunately my boiler (Apollo Fanfare) just slips through the scrappage net - it's, allegedly, 72% efficient.

I have calculated that I will save about £175pa on my gas bill. Assuming a new boiler cost £2000 to install, it will take 11 years to recoup the outlay, ignoring the finance costs. I know it would be less than 11 years if you take into account future fuel price increases, but it's still a long time - and you don't know if the boiler will last that long.

 

[Agile]

It seems very odd that your PP boiler is not included whereas some electric ignition types are included.

I have a feeling that there may have been some manufacturer efficiency massaging going on there where the gas consumption of the pilot has somehow been conveniently forgotten.

It should not be the simple running efficiency used but the overall efficiency taking into account the pilot consumption. As the pilot consumption ( about £50 pa ) is constant then the actual efficiency will vary according to the amount the boiler is used to provide heat.

I am surprised you dont take up the argument with the EST or whoever.

Tony

 

[tamz]

Get mirror and torch; there was a second screw at the back!!!

There is on the older ones, newer ones only 1 screw and the other lug twists under a slot.

 

[D_Hailsham]

It seems very odd that your PP boiler is not included whereas some electric ignition types are included.

I have a feeling that there may have been some manufacturer efficiency massaging going on there where the gas consumption of the pilot has somehow been conveniently forgotten.

It should not be the simple running efficiency used but the overall efficiency taking into account the pilot consumption. As the pilot consumption ( about £50 pa ) is constant then the actual efficiency will vary according to the amount the boiler is used to provide heat.

The Fanfare was produced before Sedbuk Ratings were introduced, so the SAP efficiency is calculated using a formula; it is not measured. This is shown by an X in the rating column on the Sedbuk website.

I am surprised you don't take up the argument with the EST or whoever.

There are some anomalies in the system. For example: all Apollo Fanfare are shown in Sedbuk as 70% with an X. But the non-fanfare models can be either 65%/X or 72%/X. I cannot find any reason for this discrepancy.

Whether it is worth querying this is debatable. In any case, I think a qualified installer would have more chance of convincing them.

 

[Agile]

Since we understand you are retired and therefore have all day long to deal with the argument then it will potentially benefit you and would justify you dealing on a pro bono basis.

Tony

 

[D_Hailsham]

Since we understand you are retired and therefore have all day long to deal with the argument then it will potentially benefit you and would justify you dealing on a pro bono basis.

I have just realized that I misinformed you earlier when I said that the efficiency of X rated boilers was calculated using a formula; it's the other way round. The formula is used when the boiler efficiency has been measured, i.e it is an A-G rated boiler.

X rated boiler efficiencies have been predetermined (presumably by a Committee!) and are given in Table 4b of SAP 2005 Revision 3. Here is part of it - the ones in red are eligible for the £400 scrappage grant:

Gas boilers (including LPG) 1998 or later
Regular non-condensing with automatic ignition - 73%
Regular condensing with automatic ignition - 83%
Non-condensing combi with automatic ignition - 73%
Condensing combi with automatic ignition - 83%
Regular non-condensing with permanent pilot light - 69%
Regular condensing with permanent pilot light 79%
Non-condensing combi with permanent pilot light - 69%
Condensing combi with permanent pilot light - 79%
Back boiler to radiators - 65%

Gas boilers (including LPG) pre-1998, with fan-assisted flue
Low thermal capacity - 72%
High or unknown thermal capacity - 68%
Combi - 70%
Condensing combi - 83%
Condensing - 83%

Gas boilers (including LPG) pre-1998, with balanced or open flue
Wall mounted - 65%
Floor mounted, pre 1979 - 55%
Floor mounted, 1979 to 1997 - 65%
Combi - 65%
Back boiler to radiators - 65%

I may be retired, but I have better things to do with my time than argue with some nebulous committee of "experts".