Reconnecting radiators to a direct mains system

[grd1976]

Hi

I have recently removed 2 radiators when decorating, turning off the manual and lockshield valves and allowing the remainder of the system to function as normal (i did not switch off or drain the heating).

I now need to reconnect the rads and had planned to do this in the usual way (opening the control valve to fill, releasing air via the bleed valve and then opening the lockshield valve).

However, I have previous experience with a combi boiler whereby I would then have topped up the pressure in the system via the connected tap. In this case I have a system comprising a traditional Baxi Solo 50/4 RS boiler and a Copperfoam Direct mains combination tank. I am assuming that if I refit the 2 rads and let the system fill them up, the pressure will be regulated via cold water being added to the system via the combination tank automatically and all I will need to do is bleed the remaining rads in the usual way?

I would be grateful if someone could confirm that this is the case as I would refer not to do any lasting damage!!

Cheers
GD

 

[Breesey]

Your system may be sealed or open vented.

If it's sealed you will have an expansion vessel (red) somewhere and a filling loop as you saw in the other system you mentioned.
If you have this type of system refit the rads and top up while cold to 1 bar or so.

If you have an open system there will be a small tank somewhere which will automatically refill the system as you bleed the rads.

The hotwater cylinder is not connected to the boiler if it is "direct"

 

[grd1976]

Thanks for your quick reply. I cant see an expansion vessel within the vicinity of the tank just a vessel marked diaphram. Furthermore, although we have no small tank (in the loft for example), would i be right in thinking that a "combination cylinder" contains such a small tank within the top of the cylinder for automatic refilling?

I am assuming the boiler is connected to the tank, although cant be absolutely certain as the boiler is in the garage and the cylinder is in the airing cupboard.

 

[Breesey]

If you have a 'direct' combination cylinder then the water container on top of it just keeps the cylinder full.

A red vessel marked diaphragm?

Have you looked around under sink for anything that might be a filling loop (connection) to the heating circuit?

 

[grd1976]

Thanks for your help.

For clarity, the only visible features of the hot water system are the baxi solo boiler, the "Copperform Direct mains combination tank" and a blue vessel mark "Butyl diaphram Expansion Vessel". I am not aware of any red vessel or filling loop/ pressure guage. I have also checked the loft etc (i have not long moved in) and there is no evidence of any additional small tank. I have found a spec for the copperform tank on the web which appears to show the top portion as a separate tank with ball-cock and assumed that if i re-fill the reattached radiators this will be heating system will be topped up from this source (or direct from the mains)?

 

[Breesey]

Thanks for your help.

For clarity, the only visible features of the hot water system are the baxi solo boiler, the "Copperform Direct mains combination tank" and a blue vessel mark "Butyl diaphram Expansion Vessel". I am not aware of any red vessel or filling loop/ pressure guage. I have also checked the loft etc (i have not long moved in) and there is no evidence of any additional small tank. I have found a spec for the copperform tank on the web which appears to show the top portion as a separate tank with ball-cock and assumed that if i re-fill the reattached radiators this will be heating system will be topped up from this source (or direct from the mains)?

The tank on top of the hot water cylinder will only be filling the cylinder. The term 'direct' in this context means that the hot water in the cylinder is heated 'directly' by immersion heater elements.

Without actually looking at your heating system there's not much further we can go with it on here.

If you are still unable to ascertain how to fill your system you will have to call a plumber in.

 

[grd1976]

It looks that way!!

Thank you very much for your advice regarding this, it is much appreciated!