Linking two hot water cylinders

[collins3248]

Hi,
Just joined
New year project is to install new Central heating system.
Current configuration.
Solid fuel open fire with back boiler heating twin coil hot water cylinder upstairs via 28mm gravity with take off to pump feeding 2 rads, 2nd coil in cylinder not used.
Proposed Config.
Keston c170 boiler feeding Heatrae sadia megalife 210 ltr vented cylinder and 3 heating zones controlled wirelessly on a sealed circuit.

I want to keep the existing system but would like to link the DHW circuit using two 2 port zone valves (normally open on the megalife hot water outlet) and ( normally closed on the existing cylinder hot water output) or one 3 port diverter valve. This would have to be fitted so ports A and B would be inlets and port AB the outlet is this possible as HONEYWELL website says the opposite, why does flow direction have to go AB to A or B

If fire is lit pipe thermostat sense temp rise and opens NC valve and closes NO valve and at the same time de energising power to Megalife stat.
I'm not sure if I ve explained this well enough, I have done some drawings but don't know how to load them on this site.
Any thoughts would be greatly appreciated.
Thanks
Mr C

 

[ChrisR]

Use photobucket or picttiger (see faq)

This would have to be fitted so ports A and B would be inlets and port AB the outlet is this possible as HONEYWELL website says the opposite, why does flow direction have to go AB to A or B

They don't seal the ports that way round. Could use 2 x NO 2 ports, but I don't exactly follow - need that drawing!

Keston boilers can be seriously cheap. Look around for these things:

 

[Softus]

I want to keep the existing system but would like to link the DHW circuit using two 2 port zone valves (normally open on the megalife hot water outlet) and ( normally closed on the existing cylinder hot water output) or one 3 port diverter valve.

I don't understand how you're going to predict and control boiler flow if you link the two primary circuits. Are you really going to be running two boilers, or am I misinterpreting your description?

 

[collins3248]

I have done my drawings in Excel how to I create a hyperlink or send attachments tried photobucket but it only processes images I think.

 

[ChrisR]

Unless you can make a a drawing of it
you could use PrintScreen and paste into a drawing app (even Paint)
or use something like public.box.net (I think), which takes any file.

You might find if you can save excel files as HTML (ie as web page) you get a subdirectory with a .gif in it - you do with Word.

I didn't know you could draw in Excel!

 

[Softus]

You could Email it. ChrisR's Email address in his profile; mine is in mine.

 

[collins3248]

Cheers for your help fellas, I now know what print screen does. I think I,ve sent you the wrong drawing though. I'm only trying to link the DHW the heating will be run purely off the gas boiler. I am a bit dissappointed with your view of Keston are they really that bad.

 

[htgeng]

I am a bit dissappointed with your view of Keston are they really that bad.

Yup. Just ask one of my customers who has been using a bunch of fan heaters and immersion for 3 weeks while waiting for his keston C25 to be fixed.

 

[ChrisR]

Only got a partial drawing - email the file as an attachment?
How do you draw that in Excel!?
SEE

You might look at a thing I've never used, called something like a
Durnsley Neutraliser.

For a boiler that big I'd use 2 smaller ones if I had the space, 2 x 24 or 28kW say.

 

[collins3248]

I HAVE JUST FOUND THIS COMPANY CALLED HEATING INNOVATIONS ON THE WEB IF YOU LOOK AT THEIR DIAGRAM THEY USE A 3 PORT DIVERTER VALVE IN THE REVERSE FLOW SITUATION ON THEIR CONTROL PANEL
http://www.h2panel.co.uk/diagram.htm

 

[collins3248]

What do you think of this companies layout, noting the reverse flow through the 3 port valves.
http://www.h2panel.co.uk/

 

[ChrisR]

WHat are the bricked-in valves for? Two x two ports in place of the one 3 port I've left in, would be enough??
I'd be with him above who said use a header, though.

 

[collins3248]

The blue brick 3 port valve feeds hot water from either the megalife gas heated cylinder or if solid fuel alight the twin coil cylinder. The red brick 2 port valve was a bit of an after thought to utilise the second coil in the solid fuel cylinder by wiring to a switch allowing a boost function in summer months.
The durnsley system only seems appropriate for twin boiler heating circuits, as I'm only using the solid fuel boiler for DHW I was hoping to get away with just the valve setup.
Heating Query
Is backflow a problem on return lines in a zoned setup.

 

[doitall]

What a mess comes to mind

I think you should stick to the day job and get someone to design it

 

[collins3248]

I only signed up to the forum yesturday, thinking it was a place for constructive advice and a place to glean and share knowledge. The title of this website typically suggests its target market and as such if us DIYers stuck to our day jobs it would not be a very interesting site to visit. Probably end up being a site for a few experts to snipe and tell the world how clever they are.
So theres my gripe. In the mean time any ideas.