Very Quick radiator question?

[twiglett]

message withdrawn

[monkeygirl]

I think they always have to be on. That's how I've always done it (and I've had a lot of practice cos our system is so crap)

[Jzee]

yes, the heating needs to be switched on. Be carefull though to let the air out slowly otherwise hot water could spurt out.

[popsycal]

oh right - that explains why when i just did it now it didnt work

[popsycal]

should a funny smell come out when you bleed a radiator??

[popsycal]

erm - on one of the radiators, a gas type smell comes out......

[momof2]

Popsy - am texting plumber DP now - will get back to you.

[momof2]

DP says that if you blled a radiator in a system that is a couple of years old then you will get a smell due to the corrosion - it will usually be hydrogen, also sometimes radiatior have chemicals in them to stop corrosion - which will also give off a smell when they are bled.
HTH
X

[popsycal]

oh thanks sooooo much!!!

not much air seems to come out though

we only got this new combi boiler a year ago....
need it serviced as pressure gauge seems to be low...

[momof2]

Glad to help.
Do you want me to ask him about the pressure gauge?

[popsycal]

please.....it is slightly below the boumndaries that it should be in - how would this affect our system.....

[momof2]

No problem - he is on a job (please note "a" not "the" ) at the moment so as soome as he finishes I'll ask him. From my basic knowledge I think it is fairly easy to repressurise the boiler, but if it is more complicated then I think I'll send you a mail - if I may?

[popsycal]

you are a star mo2!!!

will leave it with you....
one radiator is now pretty much ok but the other two, although slightly better, are still not fully hot¬

will leave it with you!

[CountessDracula]

Does anyone know how you work out how many btus you need for a room?

[momof2]

BTU
British Thermal Unit. BTUs are typically used to rate air conditioners (and some heaters). One BTU is defined as the energy required to increase the temperature of one pound of water by one degree Fahrenheit. To convert from BTUs to KWs: use 1 watt = 3.4129BTUs. This means that for typical air-conditioners:
BTUs approx watt equivalent
6000 1.8KW
8000 2.3KW

For air conditioners the typical power consumption will be less than half their cooling rating.
As a guide: 1 person approximates to 500 BTU and one PC approximates to 500 BTU.

CD - does this help??

[CountessDracula]

Thank you! They are also heat output measurement for radiators. When choosing your rad there is some calculation you can do re the volume of your room to find out how powerful the radiator has to be. I don't know what it is though

[momof2]

Ahh, wrong tree, sorry
Will ask DP, he's bound to know.

[popsycal]

could the low pressure of the system mean that the radiators wont bleed properly? because they will not///

[luckymum]

CD...is it volume in cubic feet x 4 (or 5 for a bathroom) ? We did this a while ago for our bathroom....I think it tells you the formula on the B&Q website, sorry no time to link.

HTH

[bluebear]

we just did the btu calculation for a couple of rooms but dh has the formula - it was a little complicated...you needed to know the area of the walls, whether they are external walls or internal, the desired temperature in the room, and the average temperature on the other side of the walls IRRC.
If B and Q website doesn't have it - I can ask him for formula when he comes home!

[bluebear]

posycal - in our system we have a key to turn which lets water into the heating system and the pressure gauge then rises.
Our last house had this system too. HTH

[Ange8]

As far as I know, if you have a combi boiler and bleed the radiators, the pressure at the boiler will drop. If it is too low, you will need to put more water in the system. The boiler usually has a flexible pipe with one end permanently fixed to the boiler, and you attach the other end when you want to add water (you're not supposed to keep both ends permanently attached). Your manual will probably show how to do this, and what pressure you should try to achieve.

[momof2]

Hi Popsy,
Sorry it took a while - but here is the answer from DP
I can only assume that its a combi system and the boiler needs
repressurising through the fill loop.Either on the pipes leading up to the
boiler or built in to the boiler.With the rads she could may be turn all the
other ones off and let the pump just pump through those two.Then bleed.Also
if she has thermostatic rad valves the pins maybe stuck and she might have
to remove the heads and release the pin by tapping it down(gently) to free
it.
Hope this helps

I am off for the weekend in a bit, so if this doesn't help let me know on Monday
xx

[SofiaAmes]

popsycal, the pressure should be around 1.5bar when the system is on and not below 1 bar when it is off. If it has fallen below 1 bar when off and you haven't just bled a radiator, then you may have a leak in the system (any leaky rads/pipes?). If you don't have a leak in the system then you probably have something wrong with your boiler (faulty pressure chamber/valve). If the pressure is low that could result in your rads not getting very hot, and if the pressure gets too low, your boiler will shut itself off and not start up. You can add water with the filling loop to get the pressure up to get it started. When you add water with the filling loop, do it slowly (while the system is on if you can). If you send the pressure above 2 bar by accident, bleed a rad until it comes down to 1.5bar. The thermostatic valves are nice, but notorious for sticking and leaking and not working properly.

[popsycal]

the pressure is below 1 bar when on.......we only got it fitted last year so am quite cross

where is the fillinh loop?
should i just call an engineer?

[popsycal]

the filling loop?
anyone?