Trying to understand my UFH heating system

[Kilt]

I’ve a couple of UFH manifolds, feeding 16 zones, 3 of which are rads. 
I’ve gutted a bathroom and popped one of the rads off. 
 

When I come to put new rad on, I’m going to have to refill and re-pressurise the circuit/manifold.

A bit of research suggests this is normally done via a hydraulic hand test pump on the manifold in question. 
 

However I believe my system has a built in pressurising system (see photo and labels). so no need for buying a hydraulic pump. 

is this correct?

 

If this is correct, I can’t work out how the boiler circuit is filled/pressurised. Not issue at moment, but trying to learn.  

System is:

oil boiler -> thermal store (filled by gravity/header tank)

thermal store has system heating coil, UFH coil, as well as solid-fuel coil (unused) and standard immersion. 
 

many thanks. 

Edited January 22, 2021 by Kilt

[ProDave]

Hand pump is just for pressure testing pipes part way through install.

 

To re fill yours you just open the two valves at either end of your fill loop and watch the pressure gauge that should be somewhere nearby, probably under the expansion vessel. Turn off the fill loop when it gets to desired pressure.  Go and bleed the radiator.  You will have to repeaat a couple of times,  re pressurise and bleed again until no more air left.

[Kilt]

11 minutes ago, ProDave said:

Hand pump is just for pressure testing pipes part way through install.

 

To re fill yours you just open the two valves at either end of your fill loop and watch the pressure gauge that should be somewhere nearby, probably under the expansion vessel. Turn off the fill loop when it gets to desired pressure.  Go and bleed the radiator.  You will have to repeaat a couple of times,  re pressurise and bleed again until no more air left.

Thanks... as thought, it’s like a standard system fill/pressurise. 
 

Any thoughts on how system flow/return is filled/pressurised?

Edited January 22, 2021 by Kilt

[ProDave]

17 minutes ago, Kilt said:

Any thoughts on how system flow/return is filled/pressurised?

UFH and system flow / return are all one circuit and get filled together.

[Kilt]

15 minutes ago, ProDave said:

UFH and system flow / return are all one circuit and get filled together.

If you were to guess, where do you think circuits combine, within the thermal store? I can’t find anywhere else they join (yet), however there’s about 20-30% of pipe work I’ve yet to uncover (would mean trashing another bathroom). 

[Temp]

.

3 hours ago, Kilt said:

System is:

oil boiler -> thermal store (filled by gravity/header tank)

thermal store has system heating coil, UFH coil, as well as solid-fuel coil (unused) and standard immersion. 

 

Is there a pressure gauge near the boiler so you know its pressurised?

 

There are many different  types of store. Ours is vented so the boiler to thermal store side is filled by a cold supply to a ball valve in the header tank. 

 

[Kilt]

The thermal store is unvented, we have ball valve in part of tank for automatic fill, so by comments, there’s isn’t a coil for system, it just heats the whole 200ltr directly?

it’s a McDonald Thermflow multi fuel cylinder

 

manual doesn’t state/show a coil for system, but nor does it for UFH circuit, however our old store failed on the UFH coil (got a hole) and we got a direct replacement. 

Edited January 23, 2021 by Kilt

[PeterW]

Sounds like the system is filled from the header tank which is pretty normal. Quickest way to check is tie up the header valve and then drain off from a low point on the heating system and see what happens to the header. If the header level drops you have your answer.