S Plan Help

[rmc86uk]

Hi everyone

My father in law is having new Honeywell S Plan Controls fitted as the current ones are old/not working correctly.

I'm starting fresh with it all from the wiring centre. The only thing which has thrown me is the boiler has an interal pump as well as the standard pump upstairs in the cylinder cupboard. Do these both both need to be connected as with the S Plan diagram or do they both get wired directly into the boiler?

At the moment they are both wired into the boiler direct. I'm not sure if this is right or not as he thinks it's never been connected right since day one. The boiler is a Main HE 18.

According to an S Plan wiring diagram the non boiler pump connects in with the orange from the zone valves.

Thanks in advance.

 

[Corbs]

Hi everyone

My father in law is having new Honeywell S Plan Controls fitted as the current ones are old/not working correctly.

I'm starting fresh with it all from the wiring centre. The only thing which has thrown me is the boiler has an interal pump as well as the standard pump upstairs in the cylinder cupboard. Do these both both need to be connected as with the S Plan diagram or do they both get wired directly into the boiler?

At the moment they are both wired into the boiler direct. I'm not sure if this is right or not as he thinks it's never been connected right since day one. The boiler is a Main HE 18.

According to an S Plan wiring diagram the non boiler pump connects in with the orange from the zone valves.

Thanks in advance.

please get someone who knows what they are doing because if you read the manual for the boiler you will see its a system boiler and does not require a heating pump other than the one fitted to/on the boiler

 

[andyb]

What's the pump in the cylinder cupboard for? Is it a circulating pump?

 

[Corbs]

http://www.mainheating.co.uk/docs/main-hea-range-install.pdf

pg 14

 

[rmc86uk]

Thanks for the quick replies. I'm not a plumber but it's a pump that sits on the pipe just before the zone valves.

Corbs I have seen the manual but only looked at the connections. Does it state that it doesn't need the heating pump?

 

[davesparks]

With a modern boiler the circulating pump must be connected to the pump overrun terminal of the boiler, not the orange of the valves.
What is the pump in the airing cupboard doing? is it a circulating pump, HW secondary circulating pump, U/Floor heating pump, redundant?

 

[Corbs]

Thanks for the quick replies. I'm not a plumber but it's a pump that sits on the pipe just before the zone valves.

Corbs I have seen the manual but only looked at the connections. Does it state that it doesn't need the heating pump?

you would only need to have second the pump if you have trvs on every rad in the house/flat and no heat leak etc to save the boiler boiling (to dissipate the heat from the system)

 

[davesparks]

Thanks for the quick replies. I'm not a plumber but it's a pump that sits on the pipe just before the zone valves.

Corbs I have seen the manual but only looked at the connections. Does it state that it doesn't need the heating pump?

Was it installed at the same time as the boiler, or was it left there from a previous system?

It sounds like it is redundant and should be removed

 

[rmc86uk]

The pump in the cylinder cupboard is a circulating pump. It was replaced by a plumber about two weeks ago. The pump is red hot to touch.

Corbs it is a Main HE and not a HE A. Not sure if there is much difference?

 

[davesparks]

you would only need to have second the pump if you have trvs on every rad in the house/flat and no heat leak etc to save the boiler boiling (to dissipate the heat from the system)

No you wouldn't, the circulating pump in a system boiler replaces the separate pump.

 

[Corbs]

The pump in the cylinder cupboard is a circulating pump. It was replaced by a plumber about two weeks ago. The pump is red hot to touch.

Corbs it is a Main HE and not a HE A. Not sure if there is much difference?

a rated efficiency i believe but doest matter if it have a pump inbuilt should have one on the system unless full trv's

 

[Corbs]

The pump in the cylinder cupboard is a circulating pump. It was replaced by a plumber about two weeks ago. The pump is red hot to touch.

Corbs it is a Main HE and not a HE A. Not sure if there is much difference?

and the pipes hot as well ?

 

[rmc86uk]

I don't think the pump should be as hot as it is.

 

[Corbs]

and how do you know there is an integral pump if you don't mind me asking?

 

[davesparks]

I don't think the pump should be as hot as it is.

How hot is it? what reference are you using to know how hot it should be?
It will normally be a little bit hotter than the water in the pipework

 

[rmc86uk]

Manufacturers instructions. Two flex cables from PCB one says mains other says pump.

 

[Corbs]

Manufacturers instructions. Two flex cables from PCB one says mains other says pump.

i would double check you have a system boiler and not a heat only boiler look under the boiler and look up you should see a pump if you dont its a he boiler and wire it up like a normal s plan with the pump by the cylinder (which i think you have) , if you do you don't need the second pump and wire it up like main say

 

[davesparks]

Manufacturers instructions. Two flex cables from PCB one says mains other says pump.

Post a picture

 

[rmc86uk]

Thanks everyone I'll have to double check tomorrow night and get back to you all.

 

[rmc86uk]

Just had a look and it says this in the manual: -

4. The boiler incorporates a circulating pump and expansion vessel. It is suitable for use only on fully pumped sealed systems.

 

[Corbs]

Just had a look and it says this in the manual: -

4. The boiler incorporates a circulating pump and expansion vessel. It is suitable for use only on fully pumped sealed systems.

(no f and e tank in the loft then) wire it up as pg 14/ what ever it is in your man book then depending on what valve you have 2 or 3 port

 

[rmc86uk]

And get rid of the seperate pump in the cylinder cupboard?

 

[Corbs]

And get rid of the seperate pump in the cylinder cupboard?

yes but make double sure before you get a plumber out you have one inside the boiler and its working

 

[rmc86uk]

My Dads a Plumber and he's convinced there isn't one from the manufacturers instructions. I'm gonna have a visual check on it tomorrow and report back! Thanks.

 

[Corbs]

My Dads a Plumber and he's convinced there isn't one from the manufacturers instructions. I'm gonna have a visual check on it tomorrow and report back! Thanks.

whip the skirt off (the case)

 

[davesparks]

What is actually wrong with the system as it is, before you start mucking around with it?

 

[rmc86uk]

Circulating pump in cylinder cupboard went so that was replaced by a Plumber about two weeks ago. When pump was changed water ****ed everywhere and got onto one of zone valve which blew. He then got a second hand one from shed and fitted it. Now when he turns room stat down the heating stays on. Second hand zone valve must be faulty as well. The whole wiring centre box is broke and needs replacing. He wants to uofate update st699 programmer to a digital one. Got a complete kit for £140.

 

[davesparks]

Why not also get an experienced electrician to do the job?
Most of is will charge more to pick up the pieces of a DIY job than to do it from the outset.
Plus there is the small matter of electricity being somewhat deadly if you make the simplest of mistakes,

 

[rmc86uk]

I'm competent to follow a wiring diagram. It was just the system having two pumps that threw me. Thanks

 

[davesparks]

It's not just following a wiring diagram though.
You need to also understand the wiring regulations and how to apply them in a practical situation.

 

[rmc86uk]

I appreciate your help davesparks but this forum is about helping each other and exchanging ideas. I don't know your electrical background and you don't know mine. Straight away like most people on here you assume I am a DIY'er for asking a question. I used to come on here a lot but it's these remarks what annoy me.

 

[Corbs]

Circulating pump in cylinder cupboard went so that was replaced by a Plumber about two weeks ago. When pump was changed water ****ed everywhere and got onto one of zone valve which blew. He then got a second hand one from shed and fitted it. Now when he turns room stat down the heating stays on. Second hand zone valve must be faulty as well. The whole wiring centre box is broke and needs replacing. He wants to uofate update st699 programmer to a digital one. Got a complete kit for £140.

My Dads a Plumber and he's convinced there isn't one from the manufacturers instructions. I'm gonna have a visual check on it tomorrow and report back! Thanks.

thought you said your dad was a plumber?

 

[rmc86uk]

Plumber of 44 years. I've not spoke to him about it yet. Another Plumber does all my father in laws work but he's abroad at the moment.

 

[Leesparkykent]

Hi rmc, is it a big property with lots of rads on the central heating circuit?

 

[rmc86uk]

Yea. I've managed to find the correct documentation now. There isn't a pump inside the boiler just a standalone pump in the cylinder cupboard. The boiler manual says to wire the pump direct to the boiler pcb terminals instead of the wiring centre.

 

[Corbs]

Yea. I've managed to find the correct documentation now. There isn't a pump inside the boiler just a standalone pump in the cylinder cupboard. The boiler manual says to wire the pump direct to the boiler pcb terminals instead of the wiring centre.

yes that's right because of pump overrun to dissipate heat

 

[Leesparkykent]

Yea. I've managed to find the correct documentation now. There isn't a pump inside the boiler just a standalone pump in the cylinder cupboard. The boiler manual says to wire the pump direct to the boiler pcb terminals instead of the wiring centre.

Cool, easy then standard S-plan with pump overrun. What S-plan pack have you got out of interest?

edit: just seen op where it says honeywell.

 

[rmc86uk]

The current set up he's got a Honeywell ST699 2 channel programmer, Danfoss Room Stat, 1 x Honeywell zone valve and 1 x ACL zone valve. He wants to buy a complete new control pack which we can get a Honeywell one complete with digital programmer and wiring centre for £140. Next time I'm round I'll post a photo with the state it looks at the moment. It's bodge after bodge over the years. The wiring centre has broke with no cover and with having young grand kids he wants it all making safe.

 

[Leesparkykent]

Danfoss Central Heating S-Plan Control Pack - Hitchin Plumbing Supplies Limited

Danfoss pack for £100 and are just as good as honeywell IMO.

 

[rmc86uk]

Thanks. I'll take a look!