Boiler swap query - netaheat S plan confusion

[ArtfulBodger]

Hi All

I've got a boiler swap to do next week, taking out a netaheat 10-16 on an S plan system and I have a query that hopefully someone can give me a bit of advice on.

First off, I've never really had anything to do with S plan before, mostly all Y plan and combis. On initial inspection the boiler seems to have 1 flow and 2 returns which definitely won't suit the new boiler. All the pipework is conveniently located behind the HWC which will almost certainly have to come out. There is currently an ancient old danfoss programmer providing proper 2 channel control.

So, my query is this. Would I be better off converting to Y plan or can I simply tee the returns together and leave the rest as is?

Sorry if this is all obvious to some, I've tired downloading the specs for the netaheat but can't find them anywhere.

Cheers and TIA

 

[brumylad]

what is the existing boiler (if you can remember, I'm hopeless like that)

 

[kevplumb]

wild guess netaheat 10-16

 

[doitall]

wild guess netaheat 10-16

Got the crystal ball repaired then kev

 

[ArtfulBodger]

OK then, anyone know where I can download the netaheat spec? or, alternatlively can anyone remember installing one about 25 years ago? the primary flow and return is on the left as you're looking at it, so whats that bit of 22mm doing on the right?

Arrgh, out of my depth and not even started yet!

 

[kevplumb]

here

 

[ChrisR]

The MI are at http://www.partsarena.com/baxi/.
The boiler had 4 holes, half intended for gravity HW. Tee the returns. If you keep the S plan a replacement boiler will need a bypass - see its intructions.
Can I have/buy the old gas valve please? A deserving case needs a coil from it!

 

[ArtfulBodger]

Cheers Chris, you're welcome to the valve. I'm taking the boiler out on Wednesday so hopefully I can send it to you on Thursday.

Having looked at the spec on the partsarena site it is now clear that I got it all wrong! this is a little worrying as I replaced a netaheat only last week - I really must do something about my memory. Anyway, what was I saying .... oh yes, the CH and DHW primaries are on the top left, the combined return is on the bottom right together with the cold feed (which explains the mysterious bit of 15mm going behind the boiler).

Anyway, as I've got a fair bit of pipework to do anyway and the HWC is probably going to have to come out I am more inclined to turn it into a Y plan and be done with it, really just to simplify things. I cop the cost of 3 port valve but on the other hand I salvage two 2 ports. Any thoughts?

 

[brumylad]

taking out HWC ........I would generally suggest to the client that it might not be fit to be put back........

sorry about my first post........I my plan was to check the HE had 4 tappings

 

[PEDANTICVINDICTIVEMAN]

I am also used to y plans but find the wiring simpler on the s plan so would leave it as is and just sort the pipework, this will save fannying around with the wiring to the programmer and cylinder stat regarding the grey wire.