Central heating rads

[Aaron111]

Hi all,

My property is a 3-bed terraced with double glazing windows... It currently has no central heating, so I will get a new combi fitted shortly... However, I will be putting in the central heating. My question is, is it still necessary to have a lockshield on the hall rad? I assume that is likely the best place for a room stat (or at least it was back in the day, as far as I remember)?

On other question... is it necessary to fit all rads under the windows still? Some properties I have seen (newer ones mainly) they do not, but others they do.

Any advice would be greatly appreciated.

Thanks.

 

[fowlerboi]

Personally I would have a wireless stat on a stand and just trv everything. I have them on max in living spaces where the room stat would be so it doesn’t really make a difference. If i was fitting it in someone else's house I would probably put it in the hallway with lockshields

Radiators work better under windows and use up dead space. They can be fitted where ever you want them to be

 

[Aaron111]

Personally I would have a wireless stat on a stand and just trv everything. I have them on max in living spaces where the room stat would be so it doesn’t really make a difference. If i was fitting it in someone else's house I would probably put it in the hallway with lockshields

Radiators work better under windows and use up dead space. They can be fitted where ever you want them to be

Thanks for the prompt reply. Most helpful!

 

[Aaron111]

Just one more thing... Regarding sizing the rads for the rooms, would you put a lot of trust in the BTU calculators? There are many online, or is there a rule of thumb many use that I could follow?

Any response is greatly appreciated!

 

[oz-plumber]

Rule of thumb - with considerations.

If you stuff up a domestic heating system due to pipe sizing, you may as well give the game away.
If margins are that tight that it comes down to reducing pipe sizing to make a quid, then you're working for the wrong people or don't know how to price.

There are massive margins in pipe sizing for general domestic heating

 

[Basher]

I believe Part L of the Building Regs now mandates TRV's on all rads other than on the room/space with the thermostat!
Also system design to use a maximum flow temp of 55 deg.

Some online calculators seem better at considering insulation/ construction of the building as well as which walls are outside/ inside, and what is above and below. I think if you try a few and get similar results you should be ok!

 

[Aaron111]

Hi all, just one more question regarding the radiators...

I will fit the hallway rad with two lockshields, as that is where I believe the installer will position the room stat (dining and living room will have TRVs).

But what about the towel radiator in the bathroom? Is it also recommended to have two lockshields on the towel rail (as well as the hallway rad), or would you recommend placing a TRV on it, too?

Many thanks in advance!

 

[Basher]

But what about the towel radiator in the bathroom? Is it also recommended to have two lockshields on the towel rail (as well as the hallway rad), or would you recommend placing a TRV on it, too?

I'm not the best person to answer this.
It depends on your system design. I think if you have lockshields in the hall, and they are never fully closed, you will therefore have circulation even if all the TRV's are off, so the boiler won't be running with no circulation.
if you had TRV's everywhere, and they all close, but for some reason the stat is not satisfied (eg set higher than the TRV where it is) the boiler will run with no circulation through its heat exchanger, which can be a bad thing. So under those circumstances you would put lockshields on the bathroom rad, and that would be a bypass to allow circulation and keep the boiler happy. No doubt you know this already!
The simple answer seems to be put a TRV on the towel rail If there's not one in the hall!

A down side is that the towel rail doesn't get hot in summer because the heating doesn't run and/or the TRV is off, so your towels stay damp!
You can go 'dual fuel' and put an electric element in the rad to use in summer, remembering to close the valves, and also remember to switch the heating element off when the boiler is back on!

 

[Aaron111]

Hi Basher,

Thank you for the reply.

So the system will be a combi (I have just installed the rads and the flow and return. I used to be a heating installer about twenty years back (was Corgi then) so I felt capable of running rad circuit. Obviously I am leaving the boiler to a gas safe engineer). I will soon have the combi fitted (looking for an installer in Devon, Exeter, if anyone is interested). Personally I do not see an issue with having lock shields on both hallway rad and and bathroom towel Rad butsince I’ve been out of the game for quite some time, I just wanted to confirm.