Radiators 3/4 Hot

Brad White

how comfortable is the space? You do imply "if ever" but does that mean that the space is appreciably suffering?

It may well be that you only need 75% of your radiation and when that is warm it meets the requirements at that time, at least in the room which has the thermostat. The boiler cycles off because all is well. Pressure and temperature are satisfied or so it thinks.

It well could be a thermostat location issue or a venting issue. If a thermostat location issue, check that versus the heat loss of that room and the radiator within it.

If you do find a need to increase steam pressure, do so very slightly. This may compensate for lower venting capabilities to a point, but lower is better.

Increasing your venting rate in the "slower" radiators may be all that you need; the system can vent better overall at a lower pressure. Such a deal.

Eric Tardif

Cycling?

The pressuretrol is set at .5 lbs. When the thermostat calls for service, the burner goes on for 2 minutes waits for 10 minutes and then repeats the cycle until the thermostat is satisfied - if ever. The radiators only heat up to 3/4 of their length. The last 1/4 is cold. All the pipes are insulated.

Should I increase the pressuretrol to 1 lb.?

Eric Tardif

Can it handle really cold weather?

The rooms are comfortable and the thermostat seems to be doing ok at its present location giving us the right temperature setting. I've changed the vents to those radiators that were totally cold. Now they heat up 3/4.

My old boiler fully heated the radiators really hot and only turned on when the thermostat called. The present system cycles so much and the radiators aren't fully hot that it seems quite different than my old system.

Brad White

Then again

it is not that cold out yet. It may be running as well or better than the old one in that it is heating at a lower pressure and temperature overall. (Not really "temperature" so much as "less SF at temperature").

The cycling does not concern me at this point of the season. If you are comfortable and the fuel bills are within reason (less than the GDP of Lichtenstein), you sound like you are doing fine.

Keep us posted.

Brad

Eric Tardif

Winter will be the test.

I'm learning from here and through waiting some time that the installer knew what he was doing. I good installer is one who does what the customer wants but doesn't let the customer tell him how to make it work. Otherwise, the customer should do the installation.

Rich L

New Boiler?

If this is a new boiler Eric do you know how it was sized? If it was sized to the heat loss of the building it may be undersized. On a steam system the boiler has to be sized to the radiators. The boilers ability to produce steam has to match your radiators ability to condense steam. If not the steam will only travel so far and you'll end up with rediators not warming up completely.

As Brad stated above raising steam pressures is probably not the answer. In fact it can even have the reverse effect!

Good luck, Rich L

Eric Tardif

New Boiler

I bought a new boiler off of Craigslist for $500 (complete set up with oil burner). It's a Burnham V83 (3 section). The installer said it was more powerful than my old bigger Peerless boiler. The new one had more BTU output - if using the oil burner that came with it. Since it was converted to gas and steam, I'm wondering if the BTU output is less than the old boiler? Would increasing the pressuretrol to 1 lb. overcome that?

Brad White

Size Matters

A more basic point- had not realized this was a new installation and should have asked as Rich said. By the radiators not the heat loss. A V83 is good for 283 SF of radiation. Do you know what your last boiler rating was? If not, you have to measure and catalog your radiators by SF.

Just the radiators mind you; the boiler rating deducts 33% and holds that in reserve for piping and pick-up losses.

Increasing boiler steam pressure will not compensate for any of that.

IF the boiler is too small BUT you have more radiation than you have heat loss, you might be able to swap out some radiators to get your total SF down to where the boiler might serve you and still enough to meet the heat loss. Just a thought.

Eric Tardif

Power Gas Burner - Regulator Gone

It looks like the power gas burner's regulator may be gone. I have to switch it out to get more power. Thanks!

Eric Tardif

Thermostat was gone!

It turned out that the cycling was caused by the zone thermostat! I replaced it with a Hunter (Energy Star) thermostat and now the radiators are fully heated but the power gas burner seems to be on for a while - about the same as the old burner. So I guess everything's fine now.