S plan daigrams and good place to buy 2 port valves?

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Hello,

I recently had a plumber round to check over my boiler and service it and he noticed that my boiler was linked up incorrectly.

I have a greenstar utiltiy condensing boiler 18-25 kw boiler. My plumber explained that it was plumbed like a traditional gravity fed system rather than an S plan and was basically going to overheat.

So basically the plan is fully pumped with thermostats added for both hot water and room temperature
I need 2 x 2 valves also, pump for over run.

I looked on Honeywell for diagrams but could not find a decent one with the pipes and valves positioning . i.e. I need to run a pipe from the F&E tank straigh to the boiler but which bit!?

How far from the pump do I fit the valves?

Any good links or pdf's people could post or email me?
Thanks guys
 
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I have a greenstar utility condensing boiler 18-25 kw boiler.
Which model do you mean?

My plumber explained that it was plumbed like a traditional gravity fed system rather than an S plan and was basically going to overheat.
Do you mean that the heating is pumped and the hot water is on a separate gravity circuit from the boiler?

So basically the plan is fully pumped with thermostats added for both hot water and room temperature I need 2 x 2 valves also, pump for over run.
Do you mean a bypass valve?

I need to run a pipe from the F&E tank straight to the boiler but which bit!?
You will need two pipes: a 15mm feed from the F&E tank and a 22mm vent pipe (this hangs over the F&E tank). They are connected into the flow pipe from the boiler to the pump. The order is boiler, vent, feed, pump and the distance between feed and vent connection should not be more than 150mm. Alternatively you can use an Aerjec or similar as a junction. The feed and vent pipes normally connect just before the pump.

How far from the pump do I fit the valves?
Does not matter. the pipe from the pump will divide into two at a Tee piece - one branch to the cylinder the other to the radiators. It's usual to fit the valves close together, immediately after the Tee piece, so they can be wired into a common junction box.
 
Thanks for your reply

The full name is worcester bosch greenstar utility 18 /25.

I think the answer to the second question is yes. Currently there is one pump for the heating and no valves.

Not sure about the Bypass valve? Will I need one.

The water tank and F&E will be fed from the rising main. I'm ok with that.
The F&E will need a 22mm flow pipe from the boiler (need to work out where this is on my boiler) will take a look tonight

I only have this picture of boiler to hand (non pump side)


distance between feed and vent connection should not be more than 150mm
not sure about this?
[/img]


edit found another picture of the other side ( I have since changed the pump to a more modern one)

Old tanks I have new hot water and cold water tank to replace these decrepit old ones.
 
The full name is worcester bosch greenstar utility 18 /25.
Ah! It's an Oil boiler. I was thinking of Greenstar Gas boilers, that's why I did not recognise it.

Not sure about the Bypass valve? Will I need one.
If you have separate valves for the heating and HW circuits, you will need an automatic bypass valve

The water tank and F&E will be fed from the rising main. I'm ok with that.
The F&E will need a 22mm flow pipe from the boiler (need to work out where this is on my boiler) will take a look tonight
I was not referring to the rising main but to the connections from the F&E tank to the heating circuit. Check out this diagram:

 
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Whatever way you do pipe it up, use Honeywell Kit, certainly not the cheapest, but, YGWYPF.

Fit a wireless remote room stat if you do not have one already to save on both time and redecs.

DH
 
dont worry about pump overrun with oil boilers.its only on low water content boilers like modern gas ones.were the the heat ex cant take the heat.danfoss heatplan kit is not a bad shout for the price.do prefer honeywell.
 
OK Thanks people.
That diagram does not have a F&E tank or is it and F&E tank without cold water cistern.
I have two tanks and its just which pipe goes where!
My plumber said I would need to block off one of the 28mm pipes exiting the boiler on the right hand side, I assume this is feed and return for hot water and the 22mm pipes the other side are for the CH?

I have a three core and earth for a controller so do not necessarily need a wireless but can you recommend a particular kit, there is more than one honeywell?

Cheers!
 
Honewell do all sorts of programmers, analogue roomstats, digistats, programmable stats, thats why they are the Industry Standard (IMHO)

But, there's nowt wrong with the standard 'S' plan kit available from any Plumbers Merchants, it can always be expanded, if for instance you decide to build an extension and you need to add extra zones.

DH
 
OK Thanks people.
That diagram does not have a F&E tank or is it and F&E tank without cold water cistern.
I have two tanks and its just which pipe goes where!
The tank shown in the diagram is the F&E tank. The diagram does not show the cold water supply to the tank, just the feed from the tank to the system and the vent pipe..

My plumber said I would need to block off one of the 28mm pipes exiting the boiler on the right hand side, I assume this is feed and return for hot water and the 22mm pipes the other side are for the CH?
Read the 18/25 Installation Manual

I have a three core and earth for a controller so do not necessarily need a wireless but can you recommend a particular kit, there is more than one honeywell?
You will need a four core (Line, Neutral, CH ON, HW ON) if you have an S plan.

The Honeywell Sundial Kits do not use the latest in thermostats and timers, so I would not recommend them. Much better to buy separate components as follows

2no Honeywell V4043 zone valves
1no Honeywell L641A cylinder thermostat
1no Wiring centre or 10 way Junction Box (any make will do)

If your boiler is in a place where the temperature can drop to freezing (e.g the garage) you will need:

1no Honeywell T4360 Frost Thermostat
1no Honeywell L641B Pipe Thermostat

As for the programmer and room thermostat, there are plenty to choose from. You first have to decide if you want wired or wireless. then if you want the programmer separate from the thermostat or combined.

I suggest you go to a decent plumbers merchant and ask them to show you the various options and explain the pros and cons of each.

My own system has a Honeywell CM927 wireless programmable thermostat for the central heating and a separate single channel wired programmer (e.g Honeywell ST9100C) for the hot water, which lives in the airing cupboard.
 
Thanks D_Hailsham. A shopping list just what I needed!

The installation manual has
A- CH flow
B- Primary drain
C- CH return
D- Flue Outlet
E- Condensate outlet

Because the boiler has been piped incorrectly I am a little confused, 2x28mm
pipes which go to staright to my tank on the old gravity method must be using D and E.

So assuming the Central heating is Ok what do I do about the 28mm pipes that go straight from tank to boiler they need to be pumped also?
 
The installation manual has
A- CH flow
B- Primary drain
C- CH return
D- Flue Outlet
E- Condensate outlet

Because the boiler has been piped incorrectly I am a little confused, 2x28mm
pipes which go to straight to my tank on the old gravity method must be using D and E.
Certainly not D and E. They are the flue and condensate connections.

There are two A connections, two B connections and one C connection. Presumably the HW cylinder is connected between one A and B and the heating between the other A and C.

what do I do about the 28mm pipes that go straight from tank to boiler they need to be pumped also?
Do you mean the Hot Water cylinder? If so, both pipes will have to be removed. One connection (22mm)from the HW cylinder will go to to the outlet of the HW motorized valve. The other connects (22mm) to the return pipe from the central heating to the boiler. It must be the last connection, after all radiator connections, and have a gate valve on it so the HW can be balanced.

The diagram I posted shows the feed and vent pipes (F & H) connected to the flow pipe near the boiler. It does not matter where they connect, though it is more usual to connect them just before the pump (J).
 
Thanks again D_H
Fantastic info.
I've been shoping for more copper pipes. Jeez it's expensive better get the old tank weighed in to get some money back!

Spot on with the Hot Water cylinder.Ta

The two A and B connections are at either side of the boiler then? That helps me understand the diagram better if that's the case.

Can I re use the 28mm pipe if I fit reducers or is that a bad ideaa (I may have enough 22mm)

Shall I add a gate valve to my list?

I had another thought about adding an extra 2 port valve to separate upstairs and downstaris heating, the CH pipes split near the boiler and go up and down from a tee junction? Feel I'm sprinting before crawling a bit here.[/quote]
 
I've been shoping for more copper pipes. Jeez it's expensive better get the old tank weighed in to get some money back!
So you are changing the HW cylinder as well?

The two A and B connections are at either side of the boiler then? That helps me understand the diagram better if that's the case.
The left diagram at the top of page 18 (PDF 20) is a front view showing an A and B connection on both sides.

Can I re use the 28mm pipe if I fit reducers or is that a bad idea (I may have enough 22mm)
I would use 22mm. A and B are both 1 inch BSP connections, so you will need an adapter to 22mm.

I would use one A and C as the flow and return and block off the other A connection. One B could be used as a drain point and the other B blocked off.
Shall I add a gate valve to my list?
Yes and, if you don't have them already, what about TRVs for the radiators?

I had another thought about adding an extra 2 port valve to separate upstairs and downstairs heating, the CH pipes split near the boiler and go up and down from a tee junction?
That's called a S Plus system. If you have a large house it might be sensible (regulations say new houses must have this if the total floor area is over 150m². It's optional for replacement systems.

Controls then get more complicated as you need, as a minimum, an extra room thermostat. If you want to go the whole hog, you have separate programmable thermostats.
 
So you are changing the HW cylinder as well?

Yes. I got her from my plumber who took it out of a customers house who wanted a combi cost me £60 which wasn't bad I didn't think (who I would get out to help me sooner but he is fully booked for 5 weeks)






This is the side I need to change I think



According to page 18 they must be A and B and I'm guessing that the other one is E condensate outlet

Got the Drayton TRV 4's off ebay!

It's quite a big house and detached so might be worth going the whole hog!

Picture of pipes near boiler and where they go upstairs and downstairs

 
Here is a diagram that my plumber helped me with


On the righ t hand side it suggests that a cold feed is taken form the boiler to the f & e tank. So will this be a 22mm pipe at the base of the f &e where the old 15mm pipe was?

I take it I will still need an expansion pipe back into the F&E tank where will I tee this from?


Thanks?!
 

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