Correct Boiler Plumbing?

[kevindgas]

i personally would leave it 2 pump but correct the flow/returns at the boiler.

the vent and cold feed can be in either circuit although it is normal to see it in the water circuit

 

[ElectricEe]

I've just done a sketch of the system and it's about as physically accurate as I can get it without making a really messy drawing

I'd appreciate it if someone can look at it and make any comments

http://photos.homeinbath.co.uk/main.php?g2_itemId=7709

kevindgas suggested just making the boiler pipework correct - does the following make sense? I'm also going to get a MagnaClean installed in an attempt to make things better too.

http://photos.homeinbath.co.uk/main.php?g2_itemId=7705

The HW pump will also need wiring back to the controller does anyone have a cct diagram for a twin pumped system with cyl stat? I was looking at a Horstmann's C27 for no other reason that I used to have one in the old house but their wiring diagrams don't mention a two pump system.

Thanks,

Mark

 

[Agile]

I would suggest you correct the pipework first and see what difference that makes.

I am not completely convinced its going to solve the hot water problem.

Although asked, you have not mentioned what the effect on the hot water reheat time is when the central heating is fully hot.

Tony

 

[Norcon]

On another note: my boiler is cycling with a frequency of about 3 minutes on and 3-6 minutes off when heating just the hot water cylinder. This is clearly a problem but is it caused by the plumbing?

Could be a scaled up heat exchanger in the cylinder.
If its an old cylinder you should consider replacing it for a modern high efficiency one anyway IMO.
I would change it over to S plan.

 

[ElectricEe]

Although asked, you have not mentioned what the effect on the hot water reheat time is when the central heating is fully hot.

Thanks Tony - I missed that previous question. I don't have that data at the moment but I'll get it when I have some time.

Any ideas on the electrical wiring?

 

[Agile]

Its not that easy and depends on how your system is set up. You need at least two relays or similar.

The Grunfoss pump plan has one ready set up but normally only sold with their pump plan.

Tony

 

[bengasman]

If nothing else, either the drawing is wrong, or your cold feed is on the positive pressure side.

 

[kevindgas]

swap GF with PF so that the flows are correct
as for wiring if you PM an address to me i will send you a copy of wiring diagrams we use.

 

[doitall]

If nothing else, either the drawing is wrong, or your cold feed is on the positive pressure side.

Where the cold feed is, is about the only place it would work.

The whole installation wants re-piping, from the boiler to the cylinder.

 

[ElectricEe]

The whole installation wants re-piping, from the boiler to the cylinder.

I think you're right, however, there is one major problem with that - the kitchen. The kitchen has a new T&G oak floor and is smack bang inbetween the utility room (which has a flat roof) and the airing cupboard. Access, to say the least, would be problematic

Mark

 

[ElectricEe]

If nothing else, either the drawing is wrong, or your cold feed is on the positive pressure side.

I'm 99% sure the diagram is right. I take it having a feed on the positive pressure side will have a tendency to push water back into the head tank?

Mark

 

[doitall]

If nothing else, either the drawing is wrong, or your cold feed is on the positive pressure side.

I'm 99% sure the diagram is right. I take it having a feed on the positive pressure side will have a tendency to push water back into the head tank?

Mark

Unlikely in this case because the pump is on the return.

The missing vent on the boiler is worrying, A prv should be fitted.

 

[DP]

I would swop the blue connection at the boiler.

 

[kevindgas]

the only difference between S plan and S plan+ is the pump wiring needing to be with the motorised valve actuator (brown wire) rather than the switched live (orange wire)

Is this Honeywells S plan+ you are referring too because I don't think its wired this way.

norcon having copied the drawings this morning as requested i realised that the wiring diagram S plan+ is the 3 valve one not the 2 pump one!! (blonde moment me thinks!)

anyway the lot are winging their way to sunny bath via snail mail!

 

[ElectricEe]

Diagrams received - that's extremely kind of you and is much appreciated.

My plan for the end of next week is to replumb the boiler end, swapping the two returns and also adding a magnaflow into the return path of the CH loop.

I'll post again with the results for this modification - fingers cross there will be a vast improvement in cylinder reheat times.

Thanks again to everyone that's posted helpful comments

Mark