Moved house, not familiar with this heating system. How does it work, best set up?

[stem]

As per at @terryplumb. It will probably need a professional to troubleshoot.

I had hoped the test I suggested would result in the valve moving to its heating only position. A 3-Port valve relies on a 'hot water off' signal to close off the hot water port of the valve when hot water is not required, but the heating is still 'on'. This connection is definitely missing from Terminal 1 of your programmer....

.....and would also appear from the failure of the test to be missing from your cylinder thermostat as well. These connections would be the wires connected to the terminals shown in the black rings from the Cylinder Stat and Time Controller that are connected to the grey wire from the motorised valve.

There could of course be other faults, but this is where I would start. It could just be that someone has replaced 2 x 2-Port motorised valves that don't need a 'HW off' connection with one 3-Port motorised valve which does.

You say that you have just "moved house" by that I wonder if it is a rented property, if so, it's your landlord's responsibility to fix it.

 

[Dutch85]

That would be my theory also.

As per @terryplumb you are missing the hot water off connection from the programmer. However, there is also a second source for a hot water off signal and that's your cylinder thermostat.

View attachment 286337

With heating and hot water both set to 'on at the programmer, if you turn the cylinder thermostat to maximum, and the central heating room thermostat to maximum, the motorised valve should be in the mid position. Then, if you turn the cylinder thermostat down to its minimum position, you should hear a click from the thermostat and the valve should move to the heating only position. Does that happen?

I went back to it after an hour and the the switch had moved to "H" and the thermostat on the cylinder clicks on and off when I moved it higher/lower which changed the position of of the valve to M and H respectively.

 

[stem]

In that case, it sounds like just the 'heating off' from the programmer is missing. But odd that it didn't work when you first tried it, but did an hour later.

 

[Dutch85]

In that case, it sounds like just the 'heating off' from the programmer is missing. But odd that it didn't work when you first tried it, but did an hour later.

Thanks for your explanations. Unfortunately I'm not renting, so any repair bills land at my feet. I was thinking of keeping the system going for this winter, then replacing with a more modern combi boiler - would the existing pipe work and radiators be compatible with a combi?

What would be the fix for the missing "heating off"? Replace 3 port with a 2 port valve or would it need rewiring - is that a big job? What would be the most cost effective remedy?

 

[stem]

The 'heating off' connection from the programmer is definitely missing, so it may only be that that needs to be added. But there could be other issues elsewhere as well. For someone reasonably competent electrically, as a test, it shouldn't be too difficult to run a temporary wire direct from terminal 1 of the programmer to the motorised valves grey wire, and the system tested. Then if it's successful a new cable can be installed properly.

In most cases, the radiator pipework can be retained and used with a combi but an inspection would be required to confirm. The hot water part of the system and the motorised valve etc., would be removed.

 

[Dutch85]

The 'heating off' connection from the programmer is definitely missing, so it may only be that that needs to be added. But there could be other issues elsewhere as well. For someone reasonably competent electrically, as a test, it shouldn't be too difficult to run a temporary wire direct from terminal 1 of the programmer to the motorised valves grey wire, and the system tested. Then if it's successful a new cable can be installed properly.

In most cases, the radiator pipework can be retained and used with a combi but an inspection would be required to confirm. The hot water part of the system and the motorised valve etc., would be removed.

What would be a fair price for this work? First time I'd have had to pay for boiler system work so don't want anyone to have my pants down.

 

[stem]

It's a question that gets asked a fair bit on here and it's difficult to say as there are so many factors to consider. (Even more so for me as I'm a sparkie not a gas installer.) If you have a look at the thread here, you will see why it's difficult to estimate on a forum and get an idea of the prices some have received.

 

[Tricky-Dicky]

Hi, If you Google 'Drayton LP241' you should find instructions relating to your programmer.

 

[Dutch85]

Hi, If you Google 'Drayton LP241' you should find instructions relating to your programmer.

Thanks. I'd already found them and had set things up, but the problem is the programmer is always showing that the hot water is on whenever I try and select the heating on its own.

The valve stays in the mid position until the cylinder meets its setpoint temperature, only then will it switch to heating only.

I wonder if I could removed the motorised valve once it's turned the position to heating only, that way I could get heating without first heating the cylinder? Or does the motorised valve need to be in situ and powered for the programmer to work properly?

 

[stem]

The motorised valve has a small switch inside that operates the boiler when in the heating only position, so the head would need to remain electrically connected for the boiler to work. OK, you could (with most valves) remove the head from the valve, but the way motorised valves work is that a spring pulls the valve to the hot water only position, and the motor winds it to the centre and heating only position and keeps it there. Once the head was removed the spring would pull the valve to the hot water only position where it would stay.

 

[Dutch85]

The motorised valve has a small switch inside that operates the boiler when in the heating only position, so the head would need to remain electrically connected for the boiler to work. OK, you could (with most valves) remove the head from the valve, but the way motorised valves work is that a spring pulls the valve to the hot water only position, and the motor winds it to the centre and heating only position and keeps it there. Once the head was removed the spring would pull the valve to the hot water only position where it would stay.

Until someone can sort the wiring out I could presumably mark the default hot water position on the pipework and return the motorised valve before the engineer comes without creating any other issues?

 

[jeff the gasman]

It could be the actuator motor failed and someone has switched to g to mask the issue of no heating.
Decent engineer would sort that very quickly.

 

[stem]

That wouldn't fix the missing wire from terminal 1 of the programmer.

 

[Dutch85]

I've found a crude work around to get central heating only. I removed the thermostat from the cylinder. At first I thought to attach it to the flow pipe thinking the heat from the pipe would stop demand from the cylinder, however I realised that pressing in the metal plate on the thermostat stopped it from calling for the cylinder to be heated. A small plastic egg timer and duct tape now gives me central heating without the cylinder being heated up.

Could anyone help with setting up the radiotors please? The previous house had TRVs on all the rads.

I'm not too sure on the best way to make adjustments, in this house all the radiators have the old fashioned style non trv valve and a lockshield (the towel rail has 2 valves, no lockshiekd). What's the best way to set these up so that the downstairs radiators have priority.

We don't like the bedrooms as warm as the living room, how do I best control the bedroom rads? Turn down the lockshiekd or the valve with - /+ on it?

Also, the bathroom has quite a large towel rail and the bathroom gets like a sauna. We want to keep it warm to keep mould at bay, what's the best way to lower the temp in this given it has 2 valves?