On Tue, 09 Dec 2003 16:39:37 +0000, Andy Hall wrote:

On Tue, 09 Dec 2003 10:11:27 GMT, Moonshine
wrote:

It's that time of year when one's thoughts turn to the smoothe running of ones
CH system (sad isn't it!)

Before I go into all the details I'd just like to get some expert opinion on the
suitability of the the UPS 15-50 in my system.

The pump has been running for years on the medium setting, but I've always been
concious that the system didn't seem to be running right.

The radiators were not piping hot to the touch, the house didn't feel warm all
over, and the boiler does a lot of 1-2 minute cycling.

This means hat either the boiler thermostat has a problem or that the
heat is not being delivered from it rapidly enough. The latter can
be because of poor circulation or because the boiler is oversized/burn
rate set too high for the installation or both.

The Boiler is a GlowWorm FuelSaver 55F with a rated output between 35k & 55k
Btu/h. Its anyones guess as to what it has been set to. The manual talks about
putting a suppied self adhesive label by the data plate to record setting but
guess what I can't see one :-)




Turning to this group again over the last week or so for some tips, I've treated
myself to an IR themometer to do some proper investigation.

As I say at the moment I won't go into all the figures, but the info seemed to
sugest that the pump needed to be on maximum. I've been running it like that for
a few days and things do seem to have improved regards balance of heat even
running all the LSV's open until I'm sure what the state of play is.

My main concernes at the moment are I never see anywhere near 80 degrees C at
the input to the radiators, the boilier is cutting out when the ouput has
reached this temp. The max input to closesest rad to pump is around 70 and the
lowest is around 65. And the Boiler is still short cycling.

So before I try and rectify anything balancing like crazy I want to know if the
UPS 15-50 is powerful enough or not.

This does all point to poor circulation as at least one of the
factors.

Is the system using microbore pipe (e.g. 8mm)? This may present a
higher system resistance and require a higher pump head.

Yes it is 8mm Microbore (I put it in the Subject line but should have also
included it in the body text too for clarity sorry)


Have you checked for sludging?

What is the best way of doing this (i.e. least messy )


If you have TRVs especially, a better pump option could well be the
Grundfos Alpha. There is a 15-60 model of this which has a 6m max
head as opposed to the 5m of the UPS 15-50. It also adapts its
output to match the resistance requirements.

No TRV's


However, before doing a pump swap, I would check for why the
circulation is poor.




Cheers

Cliff

.andy

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