Add room stat to system

[bottle top]

This is my heating system as best as I can describe it:

It uses a glow worm space saver mark 2 boiler providing heating to 10 radiators ( all trv ) and hot water to a cylinder. The system is fully pumped and uses 2 two port motorised valves. I believe the temp of the radiators is currently controlled by the boiler, the HW is controlled by a cylinder stat. It also uses a drayton lifestylelp522 to control timing. I can have HW independent from CH, but must have HW on to get CH.From reading on the net this means I have a 'S' plan system???

I would like to add a drayton digistat+rf601 to my system.

The timer controller is next to the HW cylinder in a separate room from the boiler. From reading on the net I need to interrupt the call for heat from the controller to the central heating valve. Is this the correct way to go about this? is there a better way.

By the way I plan to put the room stat in the hall and turn the trv onto full.

Other questions I would be pleased if someone could answer are:
How old is my boiler?
Can I still get a manual for it?

Thanks

 

[namsag]

Yep thats what you do but take the head of the trv instead of just turning up full.

You may have to change switches on back of prrogrammer from G to P which is gravity to pumped(even though yours is fully pumped it will be set to gravity)

 

[bottle top]

Thanks mate.

Have just checked the back of the timer and it is set to P already.

After reading other posts I am starting to wonder why I have not got independent heating and hot water considering I have got a valve for each. Is this a wiring fault or is it just the way my system is.

Noticed when I removed timer there was no wires in HW connections 1+2 3 wires in 3 and 1 wire in 4 (call for heat ). Does this sound right?

I will take your advice about the trv.

 

[bengasman]

Lots of non-combi systems are poorly designed and wired up wrong, so it could well be the case that is the reason you can't have independent heating and hot water.
To get fully independent control, you need something like the Honeywell 9400, the vast majority of timers only let you turn ch and dhw on and off at will, but only at the same time i.e. you can not turn the cylinder on from 4 to 6 and the heating from 6 to 8.

You may want to consider to stick the thermostat in the lounge as that is where you spend ( I imagine) more time than in your hall. In the pre-trv era, the hall was chosen as a central point to control the house (for the 3 hours per day the heating was on).
Since you have trv's, you will have 1 "master"area (the one with the roomstat) driving a number of "slave" areas.
More details on this in FAQ

 

[bottle top]

Thanks. Will think about siting of room stat a bit more.

My understanding of my controller is that it has 2 channels allowing independent control, but Iam probably wrong.

Just realised connection 1+2 which have no wires going to them are for CH and HW satisfied. Connection 3 for HW on has 3 wires and connection 4 CH on has one wire.

When I select HW on its own the zone HW valve activates and the pump comes on. When I select CH ( HW turned off ) the CH valve activates but the pump does not come on.

Still a bit confused why I can not get independent control.

 

[twgas]

does the pump come on immediately, when you turn the water on or is there about 10sec delay?

 

[bottle top]

Thanks.

fairly sure the pump comes on straight away. I will have to double check tonight. I am in work at the moment.

Why?

 

[matt1e]

When I select HW on its own the zone HW valve activates and the pump comes on. When I select CH ( HW turned off ) the CH valve activates but the pump does not come on.

Still a bit confused why I can not get independent control.

It is not wired correctly or the microswitch in the CH zone valve is knackered, at a guess

 

[bottle top]

Thanks.

If the HW and CH are both on and the cylinder stat is satisfied the HW turns off, I can see this happen on the zone valve. However the CH stays on ie pump still turns, CH valve does not move, rads hot. Does this mean the microswitch in the CH valve is ok or do I still need to check it?

 

[D_Hailsham]

It uses a glow worm space saver mark 2 boiler providing heating to 10 radiators ( all trv ) and hot water to a cylinder.
1. How old is my boiler?
2. Can I still get a manual for it?

A1 Depends on exact model, but popbably over 20 yrars old
A2. Glow-worm do not have it on line, but they may still be able to provide a copy. Try ther Literature line 01773 596190 or Tech Support 01773 828300.

The system is fully pumped and uses 2 two port motorised valves. I believe the temp of the radiators is currently controlled by the boiler, the HW is controlled by a cylinder stat. It also uses a drayton lifestylelp522 to control timing. I can have HW independent from CH, but must have HW on to get CH.From reading on the net this means I have a 'S' plan system???

If you have two 2-port valves, it certainly sounds like an S plan. But if you cannot have CH ON by itself, there is something wrong with the wiring Here a diagrams of the S Plan layout and how it should be wired:

View media item 71 View media item 72

I would like to add a drayton digistat+rf601 to my system. The timer controller is next to the HW cylinder in a separate room from the boiler. From reading on the net I need to interrupt the call for heat from the controller to the central heating valve. Is this the correct way to go about this?

Basically Yes. But we need to sort out why you cannot have CH without HW before wiring up your shiny new RF stat.

 

[bottle top]

Thanks for the info.

Remembered a plumber who did some work for us in the past. This was the person who told me I could not have CH without HW being on. Spoke to him yesterday and he said the reason is my boiler has to be satisfied that HW is on before CH can come on. Does this sound right??

It's a glow worm space saver mark 2

Cheers

 

[D_Hailsham]

he said the reason is my boiler has to be satisfied that HW is on before CH can come on. Does this sound right??

No! If you have a fully pumped system with separate motorized valves on for HW and CH you should be able to control both separately.

Have you checked that it is piped correctly for fully pumped? The pipe leaving the pump will divide into two branches, using a T-piece, and there will be a valve on each branch. One branch going to the HW cylinder, the other to the rads.

Looking back to a previous post you said:

Just realised connection 1+2 which have no wires going to them are for CH and HW satisfied. Connection 3 for HW on has 3 wires and connection 4 CH on has one wire.

On a two valve system terminals 1 and 2 should not be connected; so that's OK. It's terminal 3 which concerns me. Normally it will have only one wire, which will connect to the cylinder stat "common" terminal (usually terminal 1). We need to find out what the other two wires do. They could be the solution to your problem. Trace the wires and post what they are connected to. Post a pic of the wiring if necessary.

 

[bottle top]

Thanks

The pipe from the pump does split into the two zone valves one going into the cylinder and the other presumably going to the CH.

I wonder about the wiring are you thinking the three wires are: one to the boiler, one to the pump and the other for the zone valve? Presumably the wire from the CH on on the timer is only operating the CH zone valve.

Aside from this I have just won a Drayton wireless digistat on ebay for £35 quid delivered.

Will trace wiring and get back.

 

[bottle top]

Ok I have traced the wiring.

Term 3 on programmer has 3 wire.

One turns pump on, one to the boiler and the other to the HW zone valve via the cylinder stat. So the pump and boiler are on even if stat is satisfied.

Term 4 on the programmer has 1 wire.

This wire activates the CH zone valve.

So HW does need to be on for CH.

There are no orange and grey wires coming out of the cable out of Zone valves. Looks like they have poss. been cut back.

Have done a rough sketch but can not get picture from my album to this post. Maybe picture is visible from my profile.

Looks to me like it needs completely rewiring if I am to get independent HW and CH.

I am thinking at the moment I need to buy a wiring centre, strip back cables on zone valves to expose grey and orange wires and start again, or is there a simpler way?

The HW zone valve is a iflo za (?) with black cable coming out of it, the
CH valve is same shape,etc but no sticker and white cable coming out of it.

Question. Am I right in thinking if neccessary I can buy new micro switches for these is neccessary?


Any advice appreciated.

 

[D_Hailsham]

Looked at both pics, they seem to be identical. That's a real pigs' breakfast.

There are no orange and grey wires coming out of the cable out of Zone valves. Looks like they have poss. been cut back.
Do all zone valves have microswitches?

No. What are the Make and model no of you valves, please?

Looks to me like it needs completely rewiring if I am to get independent HW and CH.

Agreed, but it depends on which zone valves you have.

can not get picture from my album to this post.

Just below the typing box there is a link "Show My Images". click this and it will dispay you album(s) and the pics in the album. Just click on the pic you wanted and the link will be embedded in your post.