Central heating drain point under floor direct through wall

[andreas]

Are there any requirements  ~ regulatory or otherwise ~ around central heating drain points?

 

We have to replace a leaking section of heating system pipe. It is the lowest point under the floor causing issue so complete drain down coming, but no drain points at all currently so going to be fun. Part of what has to be taken up to repair is an area with a raised floor that could be lifted easily at any time. I was thinking I could put a valve under that section so I could reach down and open it from inside and the flow fun through an open ended pipe sticking out the wall. Or I could put a valve in both flow and return and T them both into the same pipe that goes outside if that would be an advantage. Any requirement for valve type? Was thinking a gate valve rather than a drain point so it can be attached permanently to the exit pipe but is there something better?

[marshian]

  On 03/02/2025 at 20:47, andreas said:

Are there any requirements  ~ regulatory or otherwise ~ around central heating drain points?

 

We have to replace a leaking section of heating system pipe. It is the lowest point under the floor causing issue so complete drain down coming, but no drain points at all currently so going to be fun. Part of what has to be taken up to repair is an area with a raised floor that could be lifted easily at any time. I was thinking I could put a valve under that section so I could reach down and open it from inside and the flow fun through an open ended pipe sticking out the wall. Or I could put a valve in both flow and return and T them both into the same pipe that goes outside if that would be an advantage. Any requirement for valve type? Was thinking a gate valve rather than a drain point so it can be attached permanently to the exit pipe but is there something better?

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Regardless of the regs if there are any - both my ground floor flow and returns have drains out side if the house (actually under the decking in the rear garden) - conventional drain points - just foam lagged in case of freezing temps

[Super_Paulie]

i just tee'd into a leg to the last rad under the floor and passed it through the cavity wall in a sleeve with a draincock on the end right over a drain. Only used it once but i was glad i did it, thats for sure.

[marshian]

  On 05/02/2025 at 09:44, Super_Paulie said:

i just tee'd into a leg to the last rad under the floor and passed it through the cavity wall in a sleeve with a draincock on the end right over a drain. Only used it once but i was glad i did it, thats for sure.

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I originally had just a drain on either the flow or the return - Found that when I needed to modify the pipework under the floor there was still a lot of water in the pipes so fitted drain points to both.

 

Added bonus was I could run an air line to one from my garage and use a low pressure air feed to scavenge the water out of the pipes. The rads all drain fine it's just the circuit I want to clear out.

 

I've got to modify the pipes again this summer to improve the circuit (simplify and get rid of a 15mm piggy back circuit when I added another radiator and get rid of a couple of compression fittings that were used as drain points before I put the external drain points in)