Heat dump radiator plumbing question

[Penguin]

Hi

I am insulating the house with kingspan so have to move the radiators further out from the wall.

The heat dump radiator has been connected with flow and return at the bottom. This seems a bit counter intuative. Should it have flow to bottom and return to top or should I replumb it as previous ?

The house is an old Scottish Croft which has been bodged together for decades. The heating system is an external pressurised oil boiler. Any suggestions appreciated.

Chris

 

[Ric2013]

Please define what you mean by a 'heat dump radiator' as I'm not clear what you think the problem is. Ta.

 

[Best]

Hello Penguin,
An oil boiler does not need a “heat dump radiator”, as you term it.
Oil boilers are electric thermostat controlled to shut off completely.
So the way the radiator is piped is irrelevant.
Some systems will require a bypass valve and perhaps a permanently open radiator somewhere for to operate as a bypass or for an area where a wall stat controls the entire zone.

 

[SimonG]

Might have been heat leak off of old solid fuel system but wont be now.

 

[Penguin]

This is a radiator with two lock shield valves connected to the bottom . Not sure if it is supposed to be a heat dump or heat leak off rad. Therre is evidence of an old solid fuel system, and it might date from this. It is a 600 x 500 rad in a corridor.

The question I would really like the answer to is;

Is there a reason why this rad is connected with flow and return at the bottom or should I connect it with one at the top and one at the bottom like the rest.

 

[Chuck]

Is there a reason why this rad is connected with flow and return at the bottom or should I connect it with one at the top and one at the bottom like the rest.

The only reason I can think of to change from the existing would be if the boiler's installation instructions specified it. This might be the case with a solid-fuel boiler where gravity circulation is needed to keep the system safe during a power cut.

Bottom-in bottom-out is the usual arrangement for a two-pipe pumped system. Modern systems don't usually have heat dump radiators. These days they have been superseded by more sophisticated controls and an automatic bypass valves (ABV).

If you are substantially changing the insulation of the dwelling, it might be a good time to get a heating engineer to do a heat loss calculation and see what they recommend as far as updating the heating and controls.

 

[SimonG]

Do you have a one pipe system? That is radiators fed out of one pipe below the radiator?

TBOE (top, bottom, opposite ends) is the most efficient way of piping radiators. But aesthetically it's not the prettiest.

BBOE (bottom, bottom, opposite ends) is the norm.

I cant think of a reason why you cant change it if you want.

 

[Penguin]

Do you have a one pipe system? That is radiators fed out of one pipe below the radiator?

TBOE (top, bottom, opposite ends) is the most efficient way of piping radiators. But aesthetically it's not the prettiest.

BBOE (bottom, bottom, opposite ends) is the norm.

I cant think of a reason why you cant change it if you want.

Thanks all for your answers. Rad has now been plumbed "as was". It was a bit of a numpty question but I appreciate all of your replies. It is a two pipe system.

I did not realise that BBOE was an option. The rad is probably a relic of an old solid fuel system.

At some point the house will get a new "green" heating system and will involve an assessment by a heating engineer, at the moment I am insulating the plaster on hard walls and insulating the uninsulated pipe runs in the solum and hope to save about 30% on fuel bills and emissions.....

Thanks again for all replies.

 

[Ric2013]

Yes, BBOE is an option. Personally I prefer TBOE as it is easier to access the control valve/ the TRV is better placed to respond to room temperature. Some do not like the look of TBOE. TBSE can look nice if carried out correctly, and arguably gets the most heat output from a radiator of given size; experience suggests this method works better with some designs of radiator than others, and it is very uncommon in the UK, though common in, for example, Italy.

From what you say I suspect the radiator may be there to act as a bypass (allowing a minium flow when all other radiators are shut off) and, if so, it does not matter where the valves are.