I've been in my current house for 5 yrs but never bothered looking at my
CH
system, but recently my pump failed ( impeller snapped of shaft ). I think
this is probably an effect of the system not running properly however, so
I've decided to pay attention to it and figure out what should & shouldn't
be happeneing.
In order to try and get some clear answers, I've done some sketches and
provided links to support my questions :-

http://freespace.virgin.net/ian.jarvo/piping arrangement.pdf

http://freespace.virgin.net/ian.jarvo/Valve & Thermo diagrams.pdf

http://freespace.virgin.net/ian.jarvo/wires.jpg

http://freespace.virgin.net/ian.jarvo/wiring layout.pdf


Q1. Does the hot water circuit use pump or just gravity?

Q2. Should switching to HW on my control unit make the motorized
valve
shut ( & trip off the pump if answer to item #1 is gravity )?

Q3. On the valve, does switching from auto to manual make valve shut
or
stay open?

Q4. Is one of the 22m pipes in the piping arrangement just the vent
to
my header tank?

Q5. Why have a -15°-+10 thermostat in the garage? , but none in the
house , and in which parameters does it work.

Q6. Further #5 I don't have an internal thermostat. Would I benefit from
intalling one Please describe where it should be hooked up to.

Q7. Instead of an internal thermostat, would a string of
thermostatically
controlled radiator valves make more sense?

Q8. Roughly how much would a thermostat cost compared to individual
radiator valves?

Q9. What point do you typically drain the system from ? Should there
be
a 'y' valve somewhere that I could stick a hose pipe on?

Q10. I've never attempted to put any corrosion inhibitor into the header
tank and there's no filtration of any kind inthe system. Should there be
either ?

Q11. For future maintenance of pump/valve/boiler, would my system benefit
from some isolation valves installed on the garage wall per my piping
sketch. Please advise where I might put one or two valves to avoid having
to
frequently drain the whole system when things go wrong.



More questions will result from the answers I receive



Please cc newsgroup responses to



Thanks in advance



IJ