Are these CH or HW pipes?

[AdFromEssex]

Evening all.

Just wondering if anyone can give me an idea what these pipes may be, please:

House built c1905. Concrete floor (rest of the house has floorboards).
These are within a kitchen cupboard that is against the party wall, roughly opposite the original kitchen back-door.

The boiler HW is a 15mm pipe but the downstairs bath hot and cold are both 22mm, those pipes emerging from the concrete floor (and leaving me scratching my head as to where it goes in to the floor and becomes 22mm!).

When I’ve run the hot water, none of these pipes feel warm.

Ideally I’d like to put an integrated fridge-freezer where this larder cupboard is, so I guess I’ll have to place the carcass on taller legs/plinth.

Any opinion welcome.

Cheers,
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[Deleted member 267285]

It could be either or both, running hot water - they won’t get warm because they’re capped. Do you have a combi boiler?

 

[Mottie]

I have something like that in my loft from when they removed the cold water storage and central heating header tanks and they converted my system to unvented hot water/sealed heating system.

 

[Harry Bloomfield]

When I’ve run the hot water, none of these pipes feel warm.

Put a digital thermometer probe in close contact with that upside down U, then try running the various - hot water taps, cold water taps, heating system - then note if the temperature reading changes, with each item turned on. A bit of pipe insulation will keep the temperature probe tip in close contact with the pipe.

 

[Deleted member 267285]

Put a digital thermometer probe in close contact with that upside down U, then try running the various - hot water taps, cold water taps, heating system - then note if the temperature reading changes, with each item turned on.

Still won’t register if they’re dead legs on the hot or cold water.

 

[AdFromEssex]

It could be either or both, running hot water - they won’t get warm because they’re capped. Do you have a combi boiler?

Hello. Yes, it’s a combi boiler, and the house is divided up in to a flat upstairs and down if that’s makes any difference.

Put a digital thermometer probe in close contact with that upside down U, then try running the various - hot water taps, cold water taps, heating system - then note if the temperature reading changes, with each item turned on. A bit of pipe insulation will keep the temperature probe tip in close contact with the pipe.

Cheers - I will get a thermometer on there and see if I get any change in the reading.

And ‘dead legs’ - do these come about when people decide to reroute their pipes, leaving the old ones to just get capped off, then? If so I wonder if that’s what has happened to the cold feed underneath the sink.

 

[Harry Bloomfield]

And ‘dead legs’ - do these come about when people decide to reroute their pipes, leaving the old ones to just get capped off, then? If so I wonder if that’s what has happened to the cold feed underneath the sink.

They are sections of pipe, which although still live, have no through flow of water. They are bad, in that for drinking water pipework, they can allow Legionella to breed in the pipe with no actual through flow.

 

[Mottie]

Yes, it’s a combi boiler,

Could the pipework be where it’s replaced a heat only boiler and conventional system?

 

[Madrab]

If it was to follow any logic, that may be for an old hot water cylinder. The 1/2" capped pipe could be a cold feed that may have risen up to the old CW cistern, the 3/4" capped could be the old HW and looped one could be the old CH flow/return

 

[AdFromEssex]

They are sections of pipe, which although still live, have no through flow of water. They are bad, in that for drinking water pipework, they can allow Legionella to breed in the pipe with no actual through flow.

Oh I think I understand you now - they’re effectively a cul-de-sac, so they don’t lead anywhere but are now spurred off the mains?

Could the pipework be where it’s replaced a heat only boiler and conventional system?

If it was to follow any logic, that may be for an old hot water cylinder. The 1/2" capped pipe could be a cold feed that may have risen up to the old CW cistern, the 3/4" capped could be the old HW and looped one could be the old CH flow/return

This makes sense to me now, and could be the answer. I’ll run the heating and see what that looped pipe reads.

As for removing them, I presume it’s a case of carefully removing the concrete around them, having them capped / looped further down, protecting and then backfilling the hole?
Also, i presume the loop (if it is indeed CH) could be used to site a new radiator?

 

[Mottie]

Oh I think I understand you now - they’re effectively a cul-de-sac, so they don’t lead anywhere but are now spurred off the mains?



This makes sense to me now, and could be the answer. I’ll run the heating and see what that looped pipe reads.

As for removing them, I presume it’s a case of carefully removing the concrete around them, having them capped / looped further down, protecting and then backfilling the hole?
Also, i presume the loop (if it is indeed CH) could be used to site a new radiator?

I think the loop could be just a mains cold feed. It should be nothing to do with the heating system.

 

[AdFromEssex]

I think the loop could be just a mains cold feed. It should be nothing to do with the heating system.

Oh, so two 22mm pipes and two 15mm pipes flow and return?
I have just googled ‘mains cold feed’ with/without ‘Victorian house’ but nothing jumped out as looking similar, so apologies for asking questions that are probably common knowledge to most!

 

[Madrab]

TBH - It's hard to gauge unless onsite. Anything else is really just a guess.

If it was a cylinder in there then the cold feed to the cylinder would drop down from above and invariably in the same space as the cylinder a cold mains feed would rise up to the CW cistern that fed the cylinder and usually the bathroom. Those pipe could be the old CH pipes and the hot supply and rising cold feed. The capped 3/4" would normally be the hot water feed from the cylinder out to as that would alsm,ost always be run in 3/4", it's capped because that is still connected to the HW circuit but may now probably a HW dead leg.

If that looped pipe gets warm when the CH system is on then you'll know. Alternatively, turn on the cold water and then touch the pipe with a screwdriver and then put the handle end to your ear, if it's a cold water loop then you' should hear the water running though the pipe.

 

[Harry Bloomfield]

TBH - It's hard to gauge unless onsite. Anything else is really just a guess.

If the pipes are not too deeply buried, a metal detector might help trace out their route.

 

[Mottie]

Oh, so two 22mm pipes and two 15mm pipes flow and return?

The ones that are looped are a 22mm and a 15mm. Same as mine. 15mm mains cold feed to the tanks in loft, 22mm for the gravity feed from cold tank to taps and immersion Cylinder. Presumably if you’ve converted from conventional to combi, the 22mm will now be the cold feed to the boiler.