In article .com, wrote:
[snip]

Any way to get the thermostat to put out any temperature but 50
degrees? ANy idea why the W-R zone-a-flow valve did not open in
response to the thermostat, and had to be operated manually?

Clearly the valve itself is OK, since you could open it manually, so the
possibilities fall into five categories:

1) defective thermostat.
2) defective zone valve actuator.
3) defective wiring between them.
4) defective wiring supplying power to the actuator.
5) defective power transformer supplying power to the actuator.

All the thermostats in the house are W-R 125-202 -- clearly an ancient
mode. I replaced the beaten up one with one I knew worked fine (from
the zone we are no longer heating), but the darned thing does not
control temperature any better than the beaten up one.

That would appear to rule out #1 above.

Clearly, the easy course is just to ignore the problem until the
Siberian front retreats, and take it up the wazoo for paying to heat a
poorly insulated garage to 52 degrees.

Absolutely. May not be the best course :-) but it certainly is the easiest.

I checked for loose wiring on thermostat and zone-a-flow -- and
everything seems to be nice and tight.

That doesn't rule out a break somewhere in between, though.

Will upgrading to a more modern thermostat help? Or is it a deeper
wiring problem? Could it possibly be the garage zone-a-flow valve
malfunction (I checked the wiring and everything eems tight)?

No, maybe, and maybe, respectively. You could also have a failed 24V
transformer that isn't supplying any (or enough) power to the actuator.

Advice, O Home Repair Gurus, I humbly request.

What model of White-Rodgers zone valve is it? If it's not completely ancient,
you can find information about it on their web site at

http://www.white-rodgers.com/wrdhom/...ydronic_02.htm

Click the link for the zone valve you have, then find and click the
Troubleshooting link, and you'll get a short list of diagnostics that will
help you find where the problem is.

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.