No Conventional Feed and Expansion tank - Can we adapt ?

3 Mar 2006
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United Kingdom
I am helping my son renovate his first house. The Central heating boiler is a Baxi Solo (not combi) but the system does not appear to have a traditional Feed and expansion tank. The radiator in the bathroom has a feed into the "flow" pipe from a wall mounted plastic "ornamental tank"(about 3 litre capacity) which has to be topped up manually !! - there appears to be no expansion pipework at all! - Since we are refurbing the bathroom we want to replace the radiator / remove this feed tank - The hot water cylinder is an indirect one - could we simply tap into the flow and return pipework as they enter/leave the cylinder and run pipework from here to a conventional feed and expansion tank adjacent to the cold water storage tank in the loft above ? (I presume expansion pipe into Feed and feed pipe into return) PS The central heating system radiators do operate on a two pipe system.

Have I oversimplified the solution ? or could we proceed on this basis?
Plan to have heating replaced eventually but he's out of cash for a while
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These days, you can have a combined F&E and Vent pipe (run in 22mm) instead of two pipes. Where you join it on to the primary, use compression fittings, because this is where any blockage is likely to occur, so it will be nice to be able to undo it and clean it out without cutting.

Take the opportunity to give it a good chemical clean and mains flush (do "search" for guidance)

BTW, if you have separate Feed and Vent pipes, they must go into the same pipe, very close together, or you may get the pump sucking down one and pumping up the other.
Further to John D's advice:

Vent and feed (or combined) is best teed into the pipework between boiler and suction side of pump. There must be no restriction (motorised valves etc) between boiler and vent exit.
Plastic Ornamental tank :LOL: :LOL: SERVOWARM .haven`t seen one of those for years :LOL: can you post a pic..............servowarm from the early 70`s made me laugh @ the time.and again now.
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You evidently Know your stuff - I found a sticker on the boiler and then found the original heating engineer was still in business( his son now does the work) - he told me that Servowarm originally installed system in 1975 ! it also has steel pipework - Thanks for all the advice everyone no pics I'm afraid as I've returned home from my sons - we,ve decided to have a combi installed and heating re-piped now rather than later.
How sensible of you to realise that the steel pipework is a potential serious problem and its much better to get it all sorted out properly.

Make sure you get a combi with enough power to heat the water properly. I would say 28 kW as a minimum.

Well, between us all here, we cover most things ;)

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