Temperature setting?

Nick_9

I purchased a home in August and am not very comfortable in my home. I read a lot of books and am an avid reader here (Thank you all). My house just would not get warm enough. I checked the setting on my boiler (gas, hot water radiators) and it was set at 120 degrees. I understand that it should be set at 140. Is this correct? I changed it to 140 and it made it better. I have a office on the third floor that just does not get warm enough. What is the highest setting that I can set the supply? Thank you all for your help. P.S. The radiators are bled.

Al Letellier

aquastat settings

Nick, it depends on where you live and what type of system you have. Do you take domestic hot water off of the boiler?
A high of 180 degrees is common as that is usually the temp. used in sizing hot water systems. Here in Maine, a boiler with a tankless is usually set 180 low and 200 high for those extreme days like we had last week. No wonder you were uncomfortable with the setting at 120. Simply not enough temp to use the radiators to max efficiency.

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Nick_9

Temperature setting

Thanks Al, I appreciate it. I thought (I am just a homeowner) that all supplies were to be set at 140? Maybe I misread something. So 180 will not blow the pressure relief valve? It is just a gas furnace for a 1500SF house. I checked the high limit switch and that was set at 180. I live in Southern New Jersey, not wuite as cold as where you are but this cold spell is taking its toll on everybody. So, one more time. I can raise it to 180 supply and ......what ......set the high limit at 220? That is safe?

Nick_9

Temperature setting

Thanks Al, I appreciate it. I thought (I am just a homeowner) that all supplies were to be set at 140? Maybe I misread something. So 180 will not blow the pressure relief valve? It is just a gas furnace for a 1500SF house. I checked the high limit switch and that was set at 180. I live in Southern New Jersey, not quite as cold as where you are but this cold spell is taking its toll on everybody. So, one more time. I can raise it to 180 supply and ......what? ......set the high limit at 220? That is safe?

scrook_2

how many settings

does the aquastat have? One (high limit temp) only? Three (high, low & differential), other? Do you have a tankless hot water coil in the boiler too or a seperate hot water tank? What heats the rooms, baseboards or radiators I assume, not in-floor radiant?

If it has a high limit only then 180°F is a common setting, though 200° is possible. I would not set it to 220° though.

If it has three setttings and no tankless hot water the Low might be set at 120°-130° (so the boiler would stays warm) but the High would often be at 180°F as w/ the single control.

If you have a tankless coil the low would be set for perhaps 160-180° and the high for 180-200° so the boiler would always be hot enough to heat the hot water when a faucet was turned on. The hot water temperature is then controlled with a tempering valve that mixes a little cold with the hot.

It might pay to have a good hydronic tech come and look at it too, see find a pro above to see who's in your area.

Bill Nye

It Depends......

Yes that should be safe and like Al said it is very common. Is there a model number on your aquastat that you could post here?

Too low a temperature, like your 120°, could cost more for fuel and damage your chimney or flue connector. The combustion process can produce water vapor and at that low of a temperature it will condense in your boiler and the flue pipe and chimney. The water vapor and the chemical soup from combustion can be very corrosive. It may also cause frost closure in your chimney if on an outside wall.Probably not,but maybe.

Chuckles

140F is a good number for your water heater, not for the boiler.

Also, if your only problem is getting heat to the 3rd floor, I had the same problem and finally figured out that the thing to do (in my case) was to increase the water pressure. This is done via the pressure-reducing valve. Of course I am not responsible if you develop leaks in your system.

If you raise your boiler water temperature, you may get temperature fluctuations (overshoot) in the parts of the house that are doing fine now.

Mark Wolff

Aquastat settings

If your triple aquastat relay is a two knob style (low and high) set your low anywhere from 160*-180* and your high to 180*-200* (20* above your low limit. Then set your safety high limit (located on supply pipe coming out of boiler to 220*. This will allow for boiler temp overshoot without tripping out your boiler. Yes these temperatures are normal. They are actually what the boiler is designed for. The previous homeowner was probably trying to save money and lowered the temperature of the boiler.

Nick_9

temperature settings?

My aquastat has 2 settings. It is set for 140 for the circulator pump to kick on and it is set at 180 for the high limit. Can I change these settings? It is only a boiler, no domestic hot water.