Towel radiator in S-Plan plus

[echoes]

I'm thinking about having a separate zone for my upstairs heating using an S-plan plus layout. At the moment I have a conventional Y-plan for the HW and CH.

However I would like the bathroom towel radiator to heat when there is call for either downstairs CH or HW.

I can think of 2 ways of doing this:

1) add another 2 port valve for the towel radiator which opens when either the HW or d/s CH is called;

2) connect the flow to the radiator to both the HW and d/s CH flow via 2 flap check valves:

[code:1]

| check valves
|
+---------------X------+
| |
| | +---------To towel rad flow
| | |
| |-----------X------+
HW |
|
CH1
[/code:1]

Any advice on this?

 

[Andygasman2010]

I don't follow your point 2) or the diagram i'm affraid!

What I would say is don't bother with a zone valve for the towel rad, just tee into the flow pipe after the pump and use the towel rad as the bypass (lockshield rad valves open on both sides) If you want a TRV on it you'll likely need an auto bypass.

You'd only need a zone valve on the towel rad if you wanted to use it WITHOUT the rest of the heating or hot water.

 

[echoes]

Thanks.

Idea was to have the towel rad on with the downstairs heating or the HW, but NOT with the upstairs heating. I could connect the towel rad to the primary as you say, but then it would get hot with any circuit calling for heat, which is not quite what I wanted, but I may settle for, for simplicity's sake!

Here's another go at the diagram: I'm trying to achieve flow to the towel rad from 2 of the 3 circuits.

[code:1]
u/s d/s
| | check valves
| |
| +----------------X-----+
| | |
| | |to cyl. +---------To towel rad flow
| | | |
| | |------------X-----+
| | |
| | |
CH1 CH2 HW
| | |
| | |
X X X 2-port motorised valves (S plan plus)
| | |
+----+---+
|
|
|
|
PUMP
|
|
|
[/code:1]

 

[Whitespirit66]

If you have access to route the pipes in that way, I don't see why it wouldn't work. The check valves seem to have averted any backflow problems.

Make sure that the check valves are good quality full flow versions.

 

[echoes]

Thanks Whitespirit66. Pipe layout lends itself to this quite nicely, I just haven't ever attempted to use check valves on CH pipes before. I would leave them accessible for maintenance... and hope they don't stick.

Just wondering if I should actually install a motorised valve instead - then when the missus changes her mind (as is her right and my privilege, I am told), I only have to swap some wires around and not change pipes. Hmmm.

 

[Andygasman2010]

The two horizontal pipes in your diagram, I assume they are the towel rad flow/returns? You seem to have the towel rad return connected to the HW flow pipe... Or am I missinterpreting it?

I still say add it before any zone valve and put a TRV on it (with a system auto bypass) Like I said, unless you want the towel rad on on it's own there's no point in zoning it.

 

[echoes]

No, the 2 horizontal lines are both flows to the towel rad. They join and then a single pipe goes to the towel rad flow. I have not shown any returns for clarity - that's backfired!

The towel rad has its flow from both HW flow and CH2 flow. The check valves prevent CH2 from heating when only HW calls, and vice-versa.

I still say add it before any zone valve and put a TRV on it (with a system auto bypass) Like I said, unless you want the towel rad on on it's own there's no point in zoning it.

Understood, but that doesn't meet the original objective (no towel rad heat when CH1 calls). However, it wins outright on the important aspect of simplicity.