ACL Lifestyle 679H340-30l0 mid position valve woes!

[Steve82]

Hi all

We moved into a house in the summer and noticed from the get-go that our hot water was scalding hot. I tried turning the thermostat on the cylinder down but it made no difference whatsoever. I've recently discovered that this is due to an immersion heater that appears to have been continually on since we moved in (that'll explain the electricity bill!). When I discovered this, I turned the immersion heater off so the system is now dependent on the the timer (20 mins in the morning, 20 mins in the evening), however we now seem to have no hot water at all.

I've been putting the mid-position valve through it's paces to try and diagnose the problem:

When the power to the boiler is off, the actuator sits at 'W'. When the heating is on, the actuator sits at 'H'. When the heating and HW are on, the actuator still sits at 'H'. It never moves to M.

It would seem then, that I will only ever get heating with the valve as it is. Does this sound like a motor failure? I think it's the old style valve, so I guess it'll be a system drain to replace - or is there some way of avoiding this?

I've also noticed that even when the heating is off, some of the upstairs radiators remain warm (not hot). The cylinder is in the loft with the boiler downstairs.

Thanks in advance for all your help!

 

[D_Hailsham]

the system is now dependent on the the timer (20 mins in the morning, 20 mins in the evening), however we now seem to have no hot water at all.

What temperature is the thermostat on the side of the HW cylinder set to?

Do you have a modern quick heating cylinder? If not, you will be unlikely to reheat it in 20 minutes

When the power to the boiler is off, the actuator sits at 'W'. When the heating is on, the actuator sits at 'H'. When the heating and HW are on, the actuator still sits at 'H'. It never moves to M.

So the motor is working, otherwise it wouldn't move from W to H.

Can you get the hot water heating up on its own? (CH OFF, HW ON, cylinder stat turned high)?

Does the boiler go out if you then turn cylinder stat low?

 

[Steve82]

Thanks for your response D_Hailsham - I'll run through your suggested tests tonight when I get home and let you know how I get on.

Cheers!

 

[Steve82]

Update....

Last night I turned the immersion heater off and by the time we went to bed all of the remaining hot water had gone (taps running cold). I set the HW to come on this morning whilst the heating was off (which it didn't despite the timings and clock being correct?)

When I got up and saw that the HW wasn't on, I turned it on then went to the loft. The thermostat on the side of the boiler was at 50C so I turned it up and heard a click and the motor kick in. The mid-position valve actuator was still pointing to 'H' and the pipes either side of the valve were warm. The water was still cold but the radiators were warm (i.e., heating on).

Anyway, that's how the land lies this morning. Any help gratefully received!

P.S., There is a black toggle (for want of a better word) that when pushed in seems to place the actuator in the 'M' position. I'm guessing this is a manual control to allow HW and Heating if the motor fails?

 

[Agile]

Yes, if you can manually open it like then then you will get hot water when the heating is on.

To avoid confusion you should edit your post to say cylinder instead of boiler when you reset the cyl stat.

Tony

 

[oilhead]

If your valve is in the W position, then that means it is open to the cylinder. If you have hot water selected on the programmer and the cylinder stat is demanding, the boiler and pump should fire.
You need to start from scratch at the junction box and check your circuits. The fault, if there is one, is with the programmer or the cylinder stat.

Tony, the manual lever will give some heating whilst hot water is in demand, not as you have said.

 

[Agile]

Why would it not give some hot water when heating is selected?

 

[D_Hailsham]

What were the results of running the tests I suggested?

The thermostat on the side of the boiler was at 50C

50C is too low; set it to 60C.

 

[Steve82]

Thanks everyone for your input.

In response to D_Hailsham - The boiler was set to 50C this morning before I turned the hot water on. Once I had turned the HW on (with the heating remaining off) I went back into the loft and turned up the cylinder stat, at which point the pump fired up (actuator in the 'H' position) and the radiators became warm.

Assuming that the system works correctly, how long after the HW comes on should hot water be available at the tap?

We've established that the motor works so it should be able to select all three positions. Will check the wiring tonight.

Thanks again!

 

[matt1e]

the valve/programmer/system is incorrectly wired
It should not motor on hw demand and if it is moving to H then you have power on both the white and gray which you shouldn't
First,Are you sure you are turning the cylinder stat up and not down?

Matt

 

[Steve82]

The cylinder stat goes from 50C to 90C (from memory) - I definitely turned it up, which caused the pump to kick in.

 

[matt1e]

The cylinder stat goes from 50C to 90C (from memory) - I definitely turned it up, which caused the pump to kick in.

Any chance of you posting a pic of the wiring centre showing the connections?

 

[Steve82]

Will have a look tonight - I have a wiring diagram, and post tomorrow if I'm still having difficulties! Thanks

 

[oilhead]

Why would it not give some hot water when heating is selected?

With heating selected, the manual lever will be ineffective because the valve motor will have been opened fully. At best, the manual lever opens the valve halfway. In the heating position, it is past that point.

 

[Steve82]

Update:

I dug out the wiring diagrams for the system and after taking an hour or so to have a good look over the wiring at the junction box and the programmer. Everything seemed to be in place (a couple of bits that I wasn't sure about), so I didn't change anything. The girlfriend was 'politely asking' for a hot shower, so I replaced the programmer, put the mains back on and turned on the immersion.

Whilst I had the loft open etc, I thought I'd see if 'resetting' the programmer had had any effect. Sure enough, I can now get all three settings on the mid-position valve by cycling through HW, HW&Heating and Heating. We now have hot water without the immersion!

I mentioned earlier on in the week that the heating and HW hadn't come on as programmed so that also points to the programmer being at fault.

Looking on the back of the programmer it has a warranty that ended in 1998 - maybe it's time to get a new one!