On 2006-12-20 21:51:27 +0000, "DavidW" said:

Thanks for all the suggestions. I have a few more questions.

The photo at

http://i10.tinypic.com/4bggqhu.jpg

shows the inside of my airing cupboard with the main components
marked. The general layout is follows the installation manual for the
Apollo Fanfare, i.e. Combined feed/vent pipe and an auto airvent in the
primary to the HW Tank. In addition it has an Aerjec Air separator. I
can understand why this might be necessary, but dont' undersatand how
it can work with a combined feed/vent. Also it has not been installed
according to the instructions on the Circulating pumps web site, see

http://www.circulatingpumps.net/UpDocs/files/Aerjec.pdf.

So my question a

1. Is the airjec actually doing anything and if not why not?

To some extent, yes.

If air is entering the Aerjec from the boiler, some will tend to find its
way up the combined feed/vent pipe rather than the pump, but as you say,
it's not a good arrangement.

The two illustrations on the Circulating Pumps web site are the best
orientation,
but the one you have would also be OK with three modifications:

- Alter the feed/vent pipe at the loft tank so that it loops up over
the tank and makes a vent pipe only.

- Add a feed pipe (15mm is OK) from the bottom of the loft tank to the
side of the Aerjec where the pump is
now connected

- Connect the pump to the currently blocked off connection.

If you look at part 11334 on www.bes.ltd.uk you will see a diagram
showing this as a valid option.

However, since you would probably want to turn the device to put the
side pipe position next to the wall
to make a neater job, it may make more sense to rip the thing out and
install it on its side anyway (which is supposed to be a better
solution. Personally, I've used both and didn't see a difference
though.


2. Could it be the cause of my problem (banging explosions) or
contributing to it?


Is there a lot of sound of air etc. through the pump? If there
isn't, then probably not. However, I would still sort this one out as
a matter of having a clean installation.