On 4/8/18 11:40 PM, J.Albert wrote:

I've changed the DIP switch settings from the 3CPH setting
to 1CPH.
I'll see if that changes anything.


Followup to my earlier post.

The thermostat I'm using is a Honeywell "round" model T87K1007.

I was using the DIP switch setting the manual recommended.
That setting reads "High efficiency warm air (90%+), hot
water, or heat pump (3CPH)"

That was causing problems -- boiler would start, run for a
very few minutes, and shut off. The radiators wouldn't even
begin to warm up. And it would repeat this at short intervals.

I changed the DIP switch setting to "Steam or gravity
(1CPH)" to see if that would change things.
And it DID -- it makes quite a difference.
The boiler now starts, STAYS RUNNING until the radiators
warm up, and then the thermostat shuts it off.
The thermostat now keeps the boiler off until the radiators
are cool, and then cycles again properly.

Seems much better.
I won't say "that's it" yet.
But "pretty close" to how things were running before I had
problems a couple of weeks' back.

I should mention that my system isn't "steam".
It's a gas furnace/boiler, hot water, cast iron radiators.
2-story house built in 1911, no insulation, plaster walls,
original windows.

That's why I used the "gas hot water" setting first (it's
what the plumbing/heating guy set it at, I guess he was
going by the manual, too).
But that setting clearly was wrong. At least for my system.
The "steam" setting works much better.

I may investigate a programmable thermostat that allows the
user to manually set the "temperature differential" (I think
that's what it's called).
The manual for this Lux unit:
https://www.amazon.com/gp/product/B0...dbb6929419807b
.... says the swing setting can be programmed to 2.25 degrees F.

Question:
If set to the 2.25 setting, does that mean 2.25 degrees
-below- the set temp and 2.25 -above it-, as well?
That would be pretty close to "what I'm looking for".