Connecting Rayburn to boiler circuit

[eagleeye]

Just been to a customer where on of our installers fitted a new viessmann heat only. They have an issue with the boiler not switching on. Talking to the customer over the phone the problem sounded like a blockage so I suggested a powerflush. Anyway after today's visit I found that he has a Rayburn connected to the system and what was happening was that there was no flow through the boiler. Found this to be because the pump was pushing it round the hot water circuit and also round the Rayburn. I'm sure the Rayburn hasn't been fitted correctly. See attached pics. We have now sealed the system and fitted a 1.5 bar PRV as Rayburn only takes max of 1.75 bar. I had to fit a lockshield to the pipework of Rayburn into the heating system so water flowed round boiler and it fired up. Obviously Rayburn is not being used so it's ok for now until I can get a solution for this. So the customer wants to use the Rayburn to heat his heating and hot water and when that's not heating it then the boiler will. Can anyone tell me what is needed for this to work correctly

 

[exedon2]

OK I was for many years a Stanley installer/commissioner so this was everyday stuff
Which model is the rayburn? I take it's gas? was it heating the full system?

 

[eagleeye]

OK I was for many years a Stanley installer/commissioner so this was everyday stuff
Which model is the rayburn? I take it's gas? was it heating the full system?

I can get the model but no not gas. Its solid fuel. The old boiler was oil and they didn't want that anymore so went to LPG bottles with the new boiler. And yes it was and still is plumbed up to do heating and hot water

 

[SJB060685]

Looks like the Rayburn is only doing HW and cooking. When integrating multiple heat sources like this it needs to be done properly. Perhaps the easiest route is a twin coil cylinder, keeping the Rayburn open vented and sealed boiler system.
Just out of curiosity why was this not picked up on in the initial survey? I'm not blaming you but somewhere down the line this should have been picked up on.

 

[exedon2]

Need to know model as they had various outputs
Solid fuel thats a twin cylinder job I take it there is a heatleak rad?
[automerge]1602954517[/automerge]
Sorry that should read twin coil cylinder
[automerge]1602964800[/automerge]
Now I've had a spare few minutes to look at your reply solid fuel rayburn on sealed system no simple as must be open vented. Get it drained and disconnected a s a p . I would seriously try to persuade customer not to bother with interlink you are in for major grief and expense if they insist.
Will depend on output which way to go from memory they go up to 14kw

 

[SJB060685]

As I said above and as exedon2 has just agreed any solid fuel system should be on an unrestricted open vented supply as its an uncontrolled heat source. As far as I know only certain manufacturers allow solid fuel appliance on sealed system but I personally wouldn't chance it as the potential for disaster is big.
IF the Rayburn is doing both CH and HW (not uncommon, Rayburn are good at that, Aga not really) then your approach changes. However I can only see 28mm primaries feeding the HW coil, which means a twin coil cylinder will suit, of course you keep the Rayburn system open vented and feeding the bottom coil and have a sealed boiler system feed the upper coil.
Most oil burners on Rayburn request a minimum of 190 Litres, although I cant be certain on solid fuel.

 

[eagleeye]

Looks like the Rayburn is only doing HW and cooking. When integrating multiple heat sources like this it needs to be done properly. Perhaps the easiest route is a twin coil cylinder, keeping the Rayburn open vented and sealed boiler system.
Just out of curiosity why was this not picked up on in the initial survey? I'm not blaming you but somewhere down the line this should have been picked up on.

Need to know model as they had various outputs
Solid fuel thats a twin cylinder job I take it there is a heatleak rad?
[automerge]1602954517[/automerge]
Sorry that should read twin coil cylinder
[automerge]1602964800[/automerge]
Now I've had a spare few minutes to look at your reply solid fuel rayburn on sealed system no simple as must be open vented. Get it drained and disconnected a s a p . I would seriously try to persuade customer not to bother with interlink you are in for major grief and expense if they insist.
Will depend on output which way to go from memory they go up to 14kw

See attached what model it is. It does have any heat leak rad no.

 

[exedon2]

That model shows as been 6.8kw you really do need to have a conversationwith end user if they want to keep cooker a current pipework layout would be useful

 

[Brambles]

The solution is not difficult, but it needs to be properly designed with an effective control system.

In essence the Rayburn needs to have a quenching valve and the control system to prioritise solid fuel over gas. Heating Innovations are a good source of information on control valves for the latter.

We are getting an increasing number of enquires / projects from people wanting to integrate log burners and Rayburn’s ( Aga’s with back boilers) with gas backup

Please don’t take this the wrong way, but installers on such systems need to have both Gas Safe and Hetas to at least level 4.

I saw a Henley Faro stove a few weeks ago that had “burst” in a large open plan living area after having been recently coupled (not by us) to a Worcester Danesmore boiler.