Immersion warming new radiator

jayke

Hi,

We've recently had our attic converted to a room. Tonight I had the immersion on for a while and noticed the radiator in the new attic room was very slightly warm. When I put my hand on the pipe into the radiator, it was luke warm.

When I had a look in the hotpress, the hot water pipe for the new radiator is tapped off the heating pipe coming out of the hot water tank.

I know it makes sense that if the water in the cylinder is being heated by the immersion that the water in the heating pipe also in the cylinder would also get warm. Would it be normal for the heating pipes in a radiator located above the hot water cylinder to heat like this?

The radiator is located about 2m above the top of the hot water cylinder and about 2m away horizontally.

Many thanks

Sleeper12

Where is it connected to the hot? Down low at the bottom of the cylinder? half way up or the pipe coming out the top of the cylinder?

Can you post photos?

jayke

https://www.boards.ie/discussion/comment/117793684#Comment_117793684

I'm not at home at the moment, I'll try get some pictures later.

There has always been 2 pipes in the side of the tank, one about a quarter way up from the bottom and the second about a quarter way down from the top. I assume this is to connect to the 'worm' that heats the tank when the heating is on.

The new radiator seems to be tapped off of both of these pipes, about 6inches back from the tank. The one near the top is the one that is getting hot when the immersion is on and seems to be the one connected to the radiator and making it warm.

I hope that makes sense!

This an old, sealed system without zones, motorised valves etc.

Thanks

Sleeper12

The two pipes going to the side of the cylinder are the flow & return for the coil. He seems to have tapped into the coil for the another rad. This is ok if there are no zones. The water in the coil will get hot if you have the immersion on. Heat rises so the heat from the coil will rise & the rad upstairs could get slightly warm

jayke

https://www.boards.ie/discussion/comment/117794222#Comment_117794222

That makes sense, I just want to be sure I haven't got a botch job done that could be loading the immersion or could cause problems down the line.

Someone told me to look up the 3 Tee rule, I've been trying to get my head around it. This would seem to suggest that the connections for the rads shouldn't have been made where they are or is there a difference when it's a single zone system? Do you know is what I'm seeing 'Thermosyphoning'

Also, is there a risk that when I start using the heating in a few weeks that I could have reverse circulation?

Sorry for all the questions, Im trying to understand what's going on and want to be sure that I don't have problems down the line.

Thanks again.

Sleeper12

It isn't an ideal way to plum a rad. The real problems would kick in if you fitted motorized valves & wanted separate zones. The rad upstairs would be on the hot water zone rather than on the heating zone

jayke

https://www.boards.ie/discussion/comment/117794387#Comment_117794387

Thanks Sleeper, I appreciate the info. 👍

Andy From Sligo

here is my tuppence (but I aint a plumber so I could be talking shyte) but I wonder when you are putting the electric immersion on its heating up the cylinder , and it in turn is heating up the coil inside and (because you have no zone valves) the central heating pump is pushing / pulling the water through the coil in the copper immersion take and distributing the warm water to the radiator.

If you were to turn off the central heating boiler pump would the radiator still get lukewarm? why no try it and see if the added on radiator still gets luke-warm

only 1 caveat I can see is that with the electric immersion heater on you want the electric to heat up the water in the immersion tank and then store it in there. Not so much in this weather because its lovely and warm outside but if it were colder outside and you were trying to heat up the water inside the tank then the pump would be sucking in or pushing in cool water to the coil and possibly cooling down the water inside the tank you are trying to heat up. - possibly maybe not because the indirect coil is its own unit inside the immersion copper cylinder in other words the central heating water does not mix with the water in the storage cylinder otherwise when you turned on the bath or sink taps you would get horrible black sooty boiler water come out of them , which is why the CH coil in the cylinder is separate - its just there to pump boiling hot water from the boiler 'through' the coil pipes in the cylinder to heat up the water in the cylinder .

So yep its possible the electric immersion is on, heating the water for baths etc , the flame on the boiler is off , but the central heating pump is on still circulation the water through the house to rads (and coil in immersion heater) , and the coil inside the hot water cylinder is getting lukewarm and then pumping the lukewarm water from the top of the coil in the tank to the newly fitted radiator making it feel lukewarm .

Tom44

Hot water naturally rises, your cylinder is heating the coil which in turn, is heating the upstairs radiator by convection/ gravity.

Same as a backboiler in a fireplace will heat upstairs radiators with the pump off.

Pipes from the hotpress should not immediately rise up to upstairs radiator, they should be like a 🏑 hockey stick, drop down to floor level and THEN rise up to attic, this prevents circulation ( most times)

What you have is safe, just turn off radiator in the summer. A lot of attic's have this issue, not a big deal.