If you had heat on the second floor prior to replacing the thermostat,even
if it was erratic, you should first look at the new stat. Just turn it up
and down while someone is at the boiler. They should hear the relay click on
and off. If not,remove the stat and touch the R and W wires together and see
if that makes the relay. The erratic heat is probably a separate
problem,most likely caused by air in the line or an incorrectly adjusted
flow control, which prevents backfeeding from one loop to another
"Paul Franklin" wrote in message
news
On 7 Jan 2005 21:58:00 -0800, "coldguy"
wrote:
snip

Ok, your boiler makes hot water. The lower floor loop works fine, but
the upper floor loop doesn't. Both circulators are running. (Are you
sure? Sometimes with vibration is it hard to tell. Turn off the lower
floor zone by turning that thermostat way down, and make sure the
other circulator is still running.) If it's not running, then you
have a problem with the thermostat, wiring , circulator, or control.


You are not circulating water in the upper floor loop; if you were,
you'd have heat.

The feed to the upper floor is hot for a while after it leaves the
boiler probably just from conduction.

Sound like the upper floor is air locked. When you bled the upper
floor, did you get out water, or just air? If just air, you may just
need to bleed it more. Make sure you bleed every radiator.

If you never get water out of the bleeds, then the static pressure of
your system isn't high enough to overcome gravity. Make sure the
make-up water valve is open.

If you don't know what or where that is, it is probably time to call
the pro.

HTH,

Paul


The boiler is in the basement. (As my install guy explaned it) the
heating water coming out the front pipe, splitting into two, and one
going to the first floor zone, the other going to the second floor
zone. After the water makes it's way around, two pipes come back down
to the basement, each with a small pump. These pumps are hooked up to
the box that also connects the cables from the thermostats. The pipes
after the pumps join into one pipe and go back into the system. This is
the loop of warm water. Touching the pumps they are both running.

I noticed the back pipe coming down from the second floor was cold,
while the one coming down from the first floor was hot. I took this to
mean that the hot water wasn't making it's way around the system. I
'bled' the system to get rid of air in the 2nd floor zone (you could
feel air being forced out the pipes while it was being 'bled'). Now
both pipes are warm, which is good... but no heat upstairs yet!

Tracing the front pipe that pushes water from the boiler into the
upstairs rooms, I find that it starts off scolding hot, and the first
floor section is scolding hot all the way till the pipe leaves the
basement. Following the split for the second floor, it is hot
initially, but as I move farther away from the split it gets cold (even
before it leaves the basement).

What the heck could be going on? Could it be the thermostat causing
issues still? Tomorrow I'm going to pick up a voltage meter and make
sure the connections are good. Apart from that, what else could be
going wrong? I was quite surprised that the 2nd floor front pipes were
cold, given that the corresponding pipes at the end of the loop (w/ the
pumps) were warm. I made sure my installation guy explained everything
to me. Could I be misunderstanding how the system works? How could
there seemingly not be any hot water going up to the second floor, but
the pipe at the end of the loop is warm? Is the loop flowing the other
way instead (pumped up the back?)? The manual for the unit is useless.

Ok... that's about it. I'll be eternally greatful for whatever guidance
you can give me.