On Sun, 4 Dec 2005 16:51:09 +0000, Achattaway
wrote:


Thanks for the replies so far. I have checked out the following as
suggested: The wiring instructions for the thermostat do not show a
requirement for a ground at the terminals, and it does not require a
battery. An identical thermostat unit installed on the bedroom zone is
working correctly. The transformer is rated at 24V so that rating
should be fine with these thermostats. I have been monitoring excatly
what seems to be happening: The display is on and showing the current
room temperature. When I turn the dial to set the heat temp I want for
the room the flame symbol appears and a few moments later the furnace
fires up. After a short period of time the furnace cuts off, and after
another short period the valve closes. When the valve closes, that is
when the display shuts off. Several minutes later the display comes
back on the valve has reopened, the room is not yet at the requested
temperature, and the furnace may fire up again. After a short period
of time again when the valve closes the display disappears again. This
continues until either I switch the required setting to below the
current room temperature, or when the room reaches the heat setting. I
tried swapping the front panel from the bedroom zone, and the same thing
happens. I am trying to determine whether the fault lies with the valve
which is a few years old (not sure quite how old), or whether there is a
fault with the thermostat before I go to the expense of replacing one or
the other. Your suggestions are most welcome.


24 volts is normal but I really need to know how many transformers and
the VA rating of each before I can even take a guess.
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