high and low temperature settings

[Deleted User]

I just wanted to get a sense of the recommended high and low temperature spread on the thermostat for a one pipe steam system. Right now we have ours set to 67/69. The setting used to be more like 64/70 but that seemed to cause a lot more problems with water hammer.

The 69 seems a little too cold for us though and the 67 a little too hot to sleep with. So we're going to try and adjust 1 degree each way to see what happens

Anyway, what's the recommended differential? I've read that if the spread is too far it can actually be less efficient.

Jamie Hall

Generally it seems somewhere around a 3 degree spread is sort of a sweet spot. Any more and it takes too long to come back up to temperature.

That said, however, you should not be getting water hammer, even with a much wider spread. It should just take longer. There are any number of things to check to get rid of it, though. Have you gotten the book "We Got Steam Heat"? It's available through the store on this site, and also on Amazon, and is a good, easy to understand primer on steam heat.

Big Ed_4

More important is they cycle you set on an thermostat ... 3-2 cycles per hour for steam ..

nicholas bonham-carter

Is your system balanced, with the main vented properly, and is the thermostat setup for steam? The placing of the thermostat matters as well.
Can you describe what sort of thermostat you have, and where it is located?—NBC

Jamie Hall

Big Ed said:

More important is they cycle you set on an thermostat ... 3-2 cycles per hour for steam ..

Some systems -- the one in the main place I care for, for instance, are best on 1 cycle per hour. The nice big CI radiators are warm for almost that long, even in very cold weather, and it gives a long enough cycle to get everything going. Granted, the temperature swing (about a degree) is a little wider than it was with the old T87, but quite tolerable.

EBEBRATT-Ed

5 deg is about the maximum setback in cold weather