Adding a radiator to a mancave

[Gazzo14]

I would like to add an additional radiator to our central heating system.

We have an attached double garage converted to a man-cave and workshop (with dividing stud partition wall) currently not covered by the central heating.
The former is not currently user friendly in winter, and we get by with a portable convector heater.
However, the boiler is located in the workshop with the flow and return pipework conveniently accessable.

One plumber I spoke to about this said I would need a new zone and thermostat in the man cave.
Another said there was no need for a new zone and I could simply tee off the flow and return near the boiler and use a rad TRV.

The difference of opinion has left me in a quandary.
I would rather go with the simplest and least costly workable arrangement.

Some background info':-

The boiler is an Ideal Logic system boiler.
We have two 2-way zone valves: one for DHW via a Megaflo cylinder and one for the central heating.
Except for the boiler, all of the above plus the wiring centre and room stat are a long way from the garage.
I believe the boiler is not at capacity based on approximate calcs of existing rad outputs.

Since the man cave won't be used all the time I would be ok for it to only potentially receive heat based on the house room stat calling for heat, further limited by a TRV.
The pipework required would only need a short run of approx 6-8 feet to the proposed rad location.

Opinions and views gladly received.

 

[Ben-gee]

Judging by what the first plumber said I presume you are looking at primary flow and return in the workshop, with all zone valves etc far away with the cylinder?
If you tee off these primaries it just means the mancave rad would receive heat whenever EITHER the heating OR the hot water were calling for heat. I don’t see this as a problem when paired with a trv and indeed is how quite a few bathroom towel rads are plumbed in.
It is by far the cheaper option too.

 

[Gazzo14]

Judging by what the first plumber said I presume you are looking at primary flow and return in the workshop, with all zone valves etc far away with the cylinder?
If you tee off these primaries it just means the mancave rad would receive heat whenever EITHER the heating OR the hot water were calling for heat. I don’t see this as a problem when paired with a trv and indeed is how quite a few bathroom towel rads are plumbed in.
It is by far the cheaper option too.

Hi. Yes indeed, the workshop pipework is the primary flow & return. Thank you for pointing out hot water calling for heat would also deliver heat to the mancave rad. I hadn't thought of that.
Our DHW is only on for 20-30 mins twice a day to the Megaflo to give all the hot water we need, and as you say the TRV will prevent the flow to the rad when DHW is on.
Many thanks.

 

[Ben-gee]

Well the trv would only prevent flow to the rad if you turned it off!

Personally I couldn’t be bothered and would just leave the rad to come on with the hot water, if you had to increase the time period by 5 minutes so be it, but that probably wouldn’t be the case anyway.

 

[Gazzo14]

Well the trv would only prevent flow to the rad if you turned it off!

Personally I couldn’t be bothered and would just leave the rad to come on with the hot water, if you had to increase the time period by 5 minutes so be it, but that probably wouldn’t be the case anyway.

Yes, I meant during the summer months when the central heating is turned off.
I'm sure you're right that it would have a negligible effect on the DHW if I simply left the TRV on (since incidentally the room is quite cool in the summer as it's loft insulation seems to work in reverse:- it's loft space being quite a bit warmer than the room).

 

[Ben-gee]

Yes I’d do that too, just shut the radiator trv to off outside of the heating season.
I just meant I’d leave it alone during the winter.