Cold Home

Alan_3

Temperatures last night droped way below normal and several coworkers and myself found our boilers couldn't keep up. What I think is happening is that our radiators can't radiate enough heat to over come the heat loss. My questions is, will turning up the boiler temperature make any difference? Or is the problem that the radiators just won't be able to put off enough heat reguardless of the water temp?

DanHolohan

What is

the boiler temperature now?

Alan_4

Not sure

The differential is set to 190, but the gage reads about 170.

DanHolohan

How cold is it outside?

Where's home?

kk_2

boiler keeping up?

Was your boiler running continuously when this happened? If so, it wasn't even keeping up (or was just keeping up) with the temperature it was set to. In that case, the limiting factor is the boiler.

Alan_4

The Boiler Did shut off

The Boiler would shut off but the pumps would continue to run. I think that the boiler output is more than enough since I only had 1 zone running, which only has one radiator. The temp as it left the boiler was 140 (I was taking it with a kitchen themometer by touching the copper tubing, so it isn't all that acurate). The return was measuring 134. I think this tells me the radiator just can't pull off enough heat. If I were to increase the temp would the output from the radiator go up?

Alan_4

I live in Mass

the temp outside is just below zero.

Mike T., Swampeast MO

Only one zone running...

Are the rest of the zones set back considerably? If so, during really cold weather, a zone that would be adequate under normal circumstance may well lack sufficient reserve to make up for the other zones that are set way back.

Fin baseboard radiators? If not, what kind?

All else being equal, raising the temp of the radiator will increase the output.

Alan_4

Old Steam Radiators

I have three zones, one zone had a temp of 67, the other 65, and the third 63. It was the one at 63 that I was trying to get to go higher, but it just sat at 63, pump just kept running. I check for air etc, the radiator gets nice and hot with even temp.

The radiators are old steam radiators, I used to have single pipe steam but had them converted over to forced hot water. I know there is a drop in efficiency from steam to water, but I had the walls insulated and was told by the contractor this should offset the loss. Perhaps I should add in some base board.

scrook_2

temperature out

is likely closer to 170° read on the gauge (though these are not real accurate, you might trust the aquastat setting of 190° better). You are likely not making good enough contact w/ the tube/pipe. If indeed you *really* are only at 170° at the outlet then raising the temp to 190° or even 200° will increase the output of the radiators, but you do not want to get too hot in the boiler though, lest it start to boil, forming steam, and with what you have on hand can't be sure where you really are operating, so it would be best to have a pro check it out, but they'll be busier than usual w/ no heat calls.

You need to know what the temperature *really* is though first, as you do not want to I'd say is would be best to get your service guy out to look at it, but he may be a bit busier than usual with the current cold spell.

Since the boiler cycles off and on the boiler output is not too small at least. These are cast iron radiators not baseboards right? If they have radiator covers, remove them for more heat, if they are dusty in between/behind sections vacuum them.

An effective if not elegant solution for now: A common box fan, as you'd use in a window in summer, (or any fan) blowing through a radiator would increase its heat output too.

If they are copper fintube baseboards vacuum/blow the dust out of them and be sure the borttoms (and tops are not blocked (carpet particularly can block the bottoms if they are mounted too close to the flooring).

Right now Eastern MA is about 5° colder than design conditions, about as cold as you will ever see. It is due to warm up Sunday I believe, but then turn cold again. We'll see. Be glad you're not Tennessee coming up to play the Pat's Sat night though.

Try a fan on the radiatior(s). If the piping/tubing to the radiator passes through an unheated area (e.g. cellar) and is accessable but not insulated try insulating it w/ pipe insulation from a hardware store or (cough!) Home Depot.

BTW do the other zones heat fine, just this one gives trouble?

Tom Anderson

The temperature of heating water has a huge impact on heating capacity. Run it at 200F, more if possible.

Last winter in Burlington, VT, I commissioned a new boiler plant for the library. Owner called one morning with -22F temperatures saying he could only maintain low 60's in parts of the building... and they never had that problem before the new Buderous boilers were installed, and the new boiler had only 2 million Btu's, less than original 2.75 million boilers.

"The boilers are undersized!", he stated.

I did not believe it.

I found the control contractor had set HWS temperature at 180F. I told owner to bump water temp up to 200F. Control technician arrived, stated,

"You can't run hot water boilers over 180F", and refused to make adjustement. Control technician then went to air handler, reduced the cfm output, and after recording the leaving air temp, told the owner,

"Look, I made the fan put out more heat". Which, of course, only made the problem worse.

Next day, owner calls again, still cold. I came down, took owner to the basement boilers and showed him the nameplate, which clearly stated 256F max temperature at XX PSI.

Owner then "ordered" control technician to bump up temperature.

The next morning, which was even colder at about -25F, owner calls me again, this time saying his building was toasty warm everywhere.

Tom Anderson

Mike T., Swampeast MO

Is the cold zone perhaps

the kitchen?

The radiation in old kitchens is often relatively undersized because there used to be a big iron cookstove providing a lot of heat.

Converting from steam to hot water does incur a hefty loss of output due to the significantly lower temperature--plus the [fact] that iron rads start putting out more BTUs per square foot of their area at/near steam temperatures

Your contractor was right that the steam rads were usually generously sized and that increasing insulation/weatherization is [usually] enough to compensate for the loss. Are your windows in good shape with storms (if original)?

An additional or larger iron radiator would probably be a better choice than baseboard...

Remember--the dead men weren't always perfect in their sizing and other factors (windows, doors, area) in that space may well have changed over the years.

Were the rest of the zones at your desired temperature?

Karen_3

Can't get house warm

How can I adjust the aquastat on my Burnham gas hot water boiler? It is so cold out (and some of our cast iron radiators don't get very hot normally) that the boiler can't seem to get the house warmer than 58 degrees (which makes the rooms with the poor radiators icy cold and one of our pipes has already froze. I took the cover off the front of the boiler but couldn't find anything that looked like it had an adjustment except the pilot light control. What does the aquastat look like and could it be hidden? I see the temp/pressure gauge and all sorts of electronic controls and a grey metal box. Please help!

Mark Wolff

Karen

Please call a heating company to set it for you. One of the grey boxes you referred to should be the one. Some controls have a metal dial with temperatures stamped on it, the temperature at the arrow being the high limit, others have two knobs, one for low and one for high temperature limits. If improperly adjusted you could cause anything from minor damage and shorter life to your boiler, or in more serious situations, you could accidentally stop your boiler from working, and have frozen pipes and worse.

Mark Wolff

For now...

turn your aquastat up to 200* or 210*. The greater the temperature difference the faster the heat transfer, so btu's will transfer out of your radiators quicker than if it was at 170-190.

This spring though, you need to have a heating company give you options to increase you heating supply to that zone, whether you increase radiator size, add fin tube convectors, etc. That will eliminate a repeat of this problem.

Also remember that if absolutely necessary you can turn on your ELECTRIC oven to broil and leave the door open to keep a chilled house from freezing; or run your ELECTRIC dryer with the vent disconnected and blowing into the room. This is rather expensive as an ongoing heat source, but in a pinch to keep the house from freezing up when a boiler goes down it can save you big money in frozen pipes and water damage.