Boiler wiring - Danesmoor + 2 external pumps

[James Palmer]

Hi all,


I currently have the following system;
1 x worcester danesmoor 15/19 boiler with internal programmable timer, a cylinder and room stat control all built into it.
There are 2 external danfoss pumps one for HW and one for CH.


I have been lucky to get a reasonably priced worcester danesmoor utility boiler, but this doesn't have a programmable controller or inputs for the room or cyclider stat, all it has is just normal mains in (presumably to just fire up the boiler).


Now the instructions say to have a pre-wired remote 10 way junction box, which then feeds the boiler with the live/neutral/earth.
I can get a 2 channel programmable controller but how will the room and cylinder stat and then the 2 pumps be accommodated, is there a specific controller that can do all of this?
One assumption of mine is to have the pumps activated with the input from the cylinder or room stat returns.


Any help with the wiring would be appreciated.


Cheers
James

 

[davesparks]

Is this an oil boiler?

Your best bet is to get an electrician in who understands boiler controls. There is no 'controller' as you put it, just a joint box where the various parts of the control system come together and get connected.

You will need relays in the system to keep the two pumps seperate, otherwise both pumps will run every time the boiler fires. (Unless you have motorised valves which I doubt you will with a 2 pump system)

If it's gas rather than oil you get another layer of complexity with maintaining the pump overrun correctly

 

[James Palmer]

Hi Dave,
Thanks for the reply.
It is an Oil boiler, and I have an qualified boiler installer but he hasn't seen this type of arrangement before and has asked me to get an electrician, but I'm trying to understand it myself as I do understand electrics.

I can see from research that the wiring is built around a 10 way control strip - but can find nothing on how to wire up the 2 grundfos pumps, which are just 2 standard pumps?

Cheers
James

 

[Dave OCD]

As Dave said unless you have a relay or 2 x 2 port motorized valves there will be no way to prevent the heating demand from firing up the DHW pump and vice versa. I think you'd be better off based on info given to consider converting to an 'S Plan' or similar system.

 

[davesparks]

Hi Dave,
Thanks for the reply.
It is an Oil boiler, and I have an qualified boiler installer but he hasn't seen this type of arrangement before and has asked me to get an electrician, but I'm trying to understand it myself as I do understand electrics.

I can see from research that the wiring is built around a 10 way control strip - but can find nothing on how to wire up the 2 grundfos pumps, which are just 2 standard pumps?

Cheers
James

No it's not a control strip, what you are looking at is a drawing of a strip of connector blocks, there is nothing controlling about it.

You need to add additional relays to make a two pump system work, it does not feature in any of the sundial wiring plans

 

[davesparks]

As Dave said unless you have a relay or 2 x 2 port motorized valves there will be no way to prevent the heating demand from firing up the DHW pump and vice versa. I think you'd be better off based on info given to consider converting to an 'S Plan' or similar system.

Why do you think it would be better converted to S plan?
We know nothing about the plumbing in the property to know whether the two pump system is there for a reason or if it would be ok to convert it?

 

[Dave OCD]

Only an example of what might overcome the issue of the two pumps - although the pumps would have to be powered at the same time as the motor switched supply to the appropriate valves, with the orange cores of each valve common to the boiler only. I'm just trying to be constructive, it might even be one of those 'dual head' pumps for all we know.

 

[davesparks]

But two pumps is not an issue to overcome? It's just another method of doing the job.

Based on the OP it sounds like a system which is not too uncommon around here on bigger/older oil boiler installations.

 

[Leesparkykent]

http://www.plumbcenter.co.uk/wcssto....all/ti/on/Grundfos_PumpPlan_Installation.pdf

Is it a grundfos pump plan system?

 

[davesparks]

I guess in theory it's similar, but all the multi pump systems I've worked on have probably pre-dated any standard 'plan' type arrangement.

There's a house near here where the plumbers had great fun over the years adapting and extending a system which ultimately ended up with two boilers, four pumps and a handful of motorised valves.

I got the job of making it all work properly when they fitted a new boiler. Fun fun fun!

 

[James Palmer]

Hi All,
Thanks for the replies.

The 2 pumps are Grundfos UPS15-50x18 MKII, but not connected like in the link they are totally separate. They only have 3 input's L/N/E.

The pumps were put in to aid circulation as the 15/19 boiler wasn't really up to the job - I believe.
So I got a slightly bigger danesmoor (20/25) and was hoping it maybe a like for like swap, but only realised I had got the utility model so that's the reason for the questions.

Thanks

 

[davesparks]

Speak to Worcester as it may be possible to swap the control module from one to the other

 

[Leesparkykent]

Have you always had independent control over the heating and hot water?

 

[James Palmer]

yes, is that unusual?

Have you always had independent control over the heating and hot water?

 

[Leesparkykent]

yes, is that unusual?

No but without seeing the system, pipe layout, etc it's guess work.

 

[James Palmer]

Hi Lee,
yes it is this actual one, that was me being tired and it has got the black control box dangling inside the boiler, so I have it already wired effectively (I guess) and just need to hook up the L/N/E to the new boiler from this?

http://www.plumbcenter.co.uk/wcssto....all/ti/on/Grundfos_PumpPlan_Installation.pdf

Is it a grundfos pump plan system?

 

[Leesparkykent]

Hi Lee,
yes it is this actual one, that was me being tired and it has got the black control box dangling inside the boiler, so I have it already wired effectively (I guess) and just need to hook up the L/N/E to the new boiler from this?

The control box/wiring centre should be fixed external to the boiler not dangling inside.

 

[James Palmer]

The control box/wiring centre should be fixed external to the boiler not dangling inside.

That will change when I sort it ....

 

[Leesparkykent]

Post deleted.

 

[Leesparkykent]

That will change when I sort it ....

Just read the OP again and your old boiler had an internal programmer so you are going to have to get a two channel programmer. Do you have a room thermostat and cylinder thermostat?

 

[James Palmer]

Just read the OP again and your old boiler had an internal programmer so you are going to have to get a two channel programmer. Do you have a room thermostat and cylinder thermostat?

I will get a 2 channel programmer - would you recommend a particular make - in terms of reliability and ease of use, I also need a 1 channel for the immersion?
There are room and cylinder thermostats which wire into this grundfos box.

 

[davesparks]

You really need to get an electrician to sort this out, especially if you want to incorporate control of the immersion heater into the system!

 

[Leesparkykent]

I will get a 2 channel programmer - would you recommend a particular make - in terms of reliability and ease of use, I also need a 1 channel for the immersion?
There are room and cylinder thermostats which wire into this grundfos box.

No you will need a two channel programmer if you want to time the heating and hot water individually. These 3 below are the most popular makes my personal preference is the Honeywell ST9400C.

Edit:immersion? This should be separate as the boiler should be heating your hot water.
https://www.plumbarena.co.uk/produc...5VDHxFpb74a2mFft3SsN0aAua78P8HAQ#.VckIf9q9KK0

Drayton LP722 (Mk4) Programmer | Programmers | NoLinkingToThis

Danfoss FP715

 

[James Palmer]

Yes I definitely will, but I like to understand it myself...

 

[James Palmer]

No you will need a two channel programmer if you want to time the heating and hot water individually. These 3 below are the most popular makes my personal preference is the Honeywell ST9400C.

Edit:immersion? This should be separate as the boiler should be heating your hot water.
https://www.plumbarena.co.uk/produc...5VDHxFpb74a2mFft3SsN0aAua78P8HAQ#.VckIf9q9KK0

Drayton LP722 (Mk4) Programmer | Programmers | NoLinkingToThis

Danfoss FP715

I saw the drayton, looked nice, will look at the others - thanks
And immersion for the element in the cylinder, just in case the boiler fails at least I have a fallback.

 

[Leesparkykent]

I saw the drayton, looked nice, will look at the others - thanks
And immersion for the element in the cylinder, just in case the boiler fails at least I have a fallback.

The immersion is normally on a dedicated circuit with a double pole switch so you can turn it on and off as you require. If you want to you could also incorporate a timer such as

Immersion Heater Timer 24hr Grasslin IHT-GPT01 | RS Electrical Supplies