hot water with Rads off??

[shocksl]

Hi guys

how do i repressurise a combi boiler ( vokera Unica 28HE )without the radiators on?

we have taken some of the radiators off and thermostats, but foolishly we drained the whole boiler.

we dont want to put the radiators back on just yet, but require hot water for shower etc.

Is this possible? and would i need special tools or bits other than spanner?

Read more: //www.diynot.com/forums/plumbing/hot-water-without.330063/#2450236#ixzz205Amqq8H

 

[Terry lambert]

Share you have taken the radiators off the wall, make sure the valves are closed. If the thermostatic side has a 0 setting put it to that, if they have a little flake frost setting only, you will need a decorators cap as otherwise they will open when the room gets cold.
Close the air vents on the other radiators


If you have a filling loop with a silver braided hose, turn that on and bleed the radiators until you have 1 bar of pressure.

You may have an integral filling loop, which will be under the boiler, and then as above

You will need a bleed key and spanner

 

[shocksl]

thank you soo soo much.

just to clarify would the decorators cap be suffiecient on their own to keep the pipes isolated (just incase i dont shut the valves properly unknowingly).

I have two pipes that go in both sides of the rads. Shall I do the caps on both pipes?

secondly as to air vents on other radiators how do I shut them? and is it crucial this is done as there are lots of radiators in the house.


Lastly, the thermostats have been taken off the pipes. is it necessary to connnect it back on to be able to shut the valves? or could it now be done without it?

 

[shocksl]

ok sorry about that.... can anybody help with the above questions?

 

[Terry lambert]

Put the thermostatic valves back on, obviously an open pipe will leak

Read my earlier post as whether they need caps or just putting the head back on, the other end you should be able to shut them down with a spanner.

If it's decorators caps you need, they will hold the valve shut, or if you havnt got those, get some 15mm compression caps and using the existing nut and olive, put a cap on and tighten, if you have trouble with the nut and olive not reaching the cap properly, post back.

You need a bleed key to open and close your radiator air vents, they are at the top of your radiator, some on the end and some behind each panel.

Make sure they are all closed before you start, and make sure you have closed your drain cock

As your putting water in, open each valve in turn starting at the lowest one until a little water comes out, then with the pressure at 1 bar turn the filling loop off, you should the. Have hot water

 

[shocksl]

thanks mate soo much for that.

ive got the compression caps.

The thermostat is off and the pipe it was attached to is shut off. is it still necessary to put the thermostat back on? or is it okay to temp leave it off?

 

[shocksl]

sorry 1 last question where do i find the drain cock? is that the other side of the radiator? or near the boiler?

 

[Terry lambert]

If you have capped the pipe, you will not be able or need to put the thermostat back on, if your still unsure, post a picture.

Drain cock question, How did you drain your central heating?

 

[Terry lambert]

If your central heating is full of water and both valves of the rads are shut off, you just need to top up the pressure to 1 bar on the boilef

 

[shocksl]

i dont know mate, it was the plumber who did it. He's no longer to come to do the job. that's the problem and hard to get hold of him.

But the gauge on the boiler says its on 0 (vokera Unica 28HE) .

 

[Terry lambert]

Go around with the bleed key and close all the air vents just to be sure.

Look around the ground floor for a drain cock, if your not sure what one looks like, look one up on the net. Make sure it is shut. Did you see where he ran the hose from?

Good practice would be to turn it off when you detach the hose, but we can't be sure he did that.

Then fill the system as I described, opening the bleed vents in turn until water comes out and then closing them, starting at the lowest first, one of you could stay by the filling loop to make sure it does not go over 1 bar

 

[shocksl]

Hi mat thanks so much. I wasnt there when he did it. Well I will look downstairs for that.

Also in the previous post you said open the valves slightly as im filling it and in this post you said open the vents. I'm kind of confused. Can you please clarify this to me.

Also could yoou please tell me the purpose of letting them leak abit before I shut them properly? (so i know what im doing and what to be looking out for).

 

[Terry lambert]

The bleed vents on the rads: you need them closed to begin with so that water doesn't pee everywhere

You then have to open them at each rad in turn starting with the lowest first to allow air out, which will then let water in, when a small amount of water comes out ( use a cloth). This tells you that the air is all out.

Your not letting them leak, just the presence of a bit of water will tell you that the air is out

When full, bleed the rads again to make sure it's all out

Tadah

 

[shocksl]

thanks soo much my friend yur help has been instrumental.

So I ill be letting air out of the vents throughout the process of filling the water up (at the same time).

last question but not least. Is 1 the pressure i need to strive for and not more or less?

 

[Terry lambert]

You should fill it up to one bar or there abouts, a tiny bit over, say 1.2 will not be the end of the world. If you go too high you could over pressure the boiler and when the heating gets hot the water expands and will raise the pressure.

Three bar and over the pressure releif pipe opens (safety pipe) and if any grit gets in the seating it sill drip and lose pressure, which will mean paying an engineer

Don't panic, this should be a fairly easy operation, better to under pressurise it while your filling and then top up to pressure while your standing in front of the gauge.

Good luck, and your welcome