CH Boiler Problem

[Stuart B]

I have an Alpha CD 32C Boiler and a wireless controller in the hall which is fitted with a rad which has no TRV .Tonight I happened to notice that this rad was cold at the top so I bled it and there was quite a lot of air in it for some reason .

Later on I suddenly realised the flat was getting chilly and on investigating I found that the controller was calling for heat but that the rads were all cold .I went to the boiler and it wasn't providing heat and the pressure was showing as zero and the warning lights were showing ....I didn't note what the sequence was but I think it was the sequence that means a low pressure .I topped up the pressure and everything seems fine now .

It seems too much of a concidence that my bleeding this rad would not have anything to do with the boiler stopping to operate but I cannot understand why that would be and I like to know reasons for things happening .

Anyone suggest what has gone on here .

Stuart

[geoff]

In message , Stuart B

[Stuart B]

[John Rumm]

It is quite possible it was bled, but more air collected in it after. With a fresh fill of water it can take some days for all of the air to come out of suspension. The other possibility is you have insufficient (or no) corrosion inhibitor in the system and what you bled was hydrogen gas produced as a corrosion by product and not air.

[The Natural Philosopher]

You need to repressurise if you remove any volume form the closed system. By bleeding you did.

[The Natural Philosopher]

[John]

How do you prove your usefulness in the house if you are not going around checking and bleeding the radiators every few days?

[Stuart B]

But would all the air be in only one rad if that was the case ?

There was sufficient inhibitor put in the system as I was there when it was put in and know how much of the container he used . Stuart

[John Rumm]

That is quite often the case - often the highest rad in the system, or the first one etc, but it seems common to get one that favours collection of gas more than the others.

Jolly good. At least with sealed system then you won't have any problems with pumping over which can draw more air in.

[Ed Sirett]

See the SealedCH FAQ