Boiler temperature winter vs summer

RTW

I have a single pipe steam system and told the boiler is a wet system that is never drained( it has been cold skimmed over the years for maintenance). Is it proper to keep the boiler temperature 180 during heating season and 120 in the summer or non heating season

ethicalpaul

I keep mine at room temperature in the summer.

leonz

You are blessed with a simple easy to maintain heating system.

Do you have a separate hot water heater?

If you do not have a separate hot water heater, you probably have a domestic hot water coil in the boiler
and that is why the boiler is left to run the year round.

I have a coal stoker boiler for heating and domestic hot water.

A coal stoker used for heating and providing domestic hot water in Summer operates with a 140 Degree Fahrenheit Low Limit Temperature and 160 Degree Fahrenheit high limit temperature.

Mad Dog_2

The returns and mudlegs should be flushed out atleast once a year. Plus the LWCO if yiu have a #67 or 47-2.    Mad 🐕 Dog 

RTW

Thanks for responses:

I have a separate electric hot water heater. Its STATE Heater, but I lost the lower heating element recently running on the upper only at the moment. Its from 1996 and i only replaced the lower element one time, not other issues. I have good water Im told by a plumber that knows the house.

As to returns, I changed out the wet return years ago that was buried under the concrete in front of the Bilco Door that exits basement. I designed the replacement of wet return to allow it to be flushed out ( used a ball valve on the end nearest the boiler to cordon off - so to speak - then run water through the remaining buried return to clean it. Never much sediment but pease of mind

I also - years ago - abandoned the oil feed that was buried under concrete and replaced it with above grade oil feed line, so made some improvements. And, added main line vents as often mentioned on this site

I try to boil all vents every one to two years in white vinegar for 3 to 5 minutes. Those brands favored on this site is accurate and hold up

I have good water other than some Iron content that is filtered with cuno filter from the deep well. Its only cosmetic in a small way

RTW

P.S my LWCO is McDonnel Miller float type lighting drained 1X a month to check for any discolored water and checked annually by service tech. Many years ago an experienced tech cleaned the entire system flushed it with a cleaner for steam systems and emptied buckets of discolored / sludge like water through LWCO ( this too had to be cleaned afterward). Copper pipes were changed out due to age and inner build up along with holding tank. Nothings perfect but I made some positive changes.

ethicalpaul

OK sounds good, I am a big fan of not heating DHW with a massive boiler all summer long.

So why do you want to keep your boiler hot in the summer? Am I missing something?

RTW

As to why heat boiler in summer: 1) I was told its a wet system when I purchased house. My service tech told me keeping it at least warm - 120 degrees - will prevent having issues with the chimney that could affect the liner is all I know. 2) I believe Ive read on this site keeping boiler warm in summer helps to keep down corrosion inside the boiler as well - and to raise the water line in the off season.

I dont know for sure so is why I would put it out there for comment - Thanks

mattmia2

Chemical reactions proceed faster at higher temps.

If you add water to the boiler it is important to heat it to near boiling soon after adding it to drive as much dissolved oxygen out of it as possible but warmer water just corrodes things faster.

RTW

To your point, I think I fired the boiler up to 212 for awhile after adding higher water line for summer. I understand - Thanks

EdTheHeaterMan

I can't see any benefit to operating the boiler to 120° all summer long. Room temperature is fine. There are. thousands of boilers that are left cold all summer and they have lasted half a century in many cases. (Not sure I could say that about the stuff they make today). I CAN see a real disadvantage to maintaining 120° all summer. Fuel oil costs are much higher than they were in the 1950s.

RTW

I was told by my old school service tech that the warmth in the boiler - or some warmth - benefits the chimney lining from degradation. So the consensus from opinions thus far is I can turn it down even more without harm to room temp, which I like very much. I keep it at 180 in winter and 160 in fall and spring FYI - many thanks

mattmia2

just keep it at 160 and turn it off in the summer. only turn it up if it doesn't keep up with heating the house.

AdmiralYoda

My boiler is 42 years old and I've been its caretaker for 15 years now. I drain any sludge in it, flush the LWCO and top it off to about the top of the sight glass at the very end of the season. I run the system for a bit until I make some steam for awhile to drive off any excess oxygen and run a bit through the LWCO again and then let it sit until October.

If I kept it at 120 degrees my basement would probably be 10 degrees warmer than it already is. My 1885 house with dirt crawlspaces in the basement would probably smell even worse if it was 80 degrees down there. But that is another story...

EdTheHeaterMan

RTW said:

I was told by my old school service tech that the warmth in the boiler - or some warmth - benefits the chimney lining from degradation. So the consensus from opinions thus far is I can turn it down even more without harm to room temp, which I like very much. I keep it at 180 in winter and 160 in fall and spring FYI - many thanks

I see no reason to maintain any minimum temperature in a steam boiler. When there is a call for heat the temperature will go up over 200° (depending on altitude) without the help of any additional aquastat controls. As the outdoor temperature drops, the off time between cycles will not be long enough for the water to drop to 60° or 70° basement temperature. In the spring and fall, why not use longer off cycles to save a little fuel and allow it to drop below 120° or 160°?


Condensation of flue gasses is a concern for low temperature boiler operation. You don't want long running cycles of low temperature flue gas. That is why hot water systems with low temperature radiant emitters will need a bypass or other means to keep the return water high enough to solve the low temperature flue gas problem. When you make steam, the flue gas will by design get above the condensing temperature. The entire boiler is at a temperature well above 200° in order to get steam. Once that temperature is reached (usually within the first 10% of the run cycle time) any condensation in the flue gasses that may have accumulated on the boiler or chimney liner will be long gone after the steamer starts heating the building.


I believe that the information about maintaining a minimum temperature is for hot water systems, not steam systems. And by the way, there are better remedies for reducing flue gas condensation in water boiler systems, that will not use so much energy. In the 50 year life of a boiler, the fuel to maintain that minimum temperature may add up to the cost of a new boiler or two. So you waste energy to save the boiler? There is a better way. And on a steamer... You don't need it at all!

Disconnect the Aquastats

Mr. Ed

RTW

So, the consensus is that its fine to keep the boiler OFF during the non- heating season with no harm to boiler or chimney lining and raise the water level in sight glass with some operation to burn off oxygen before closing it down for the non-heating season. And, 160 temp is fine during heating season. Thank you everyone for advice. Hopefully others will benefit from this advice

ethicalpaul

I'm still a bit confused by what you mean by "160 temp is fine during heating season"

Just let it call for heat when it needs to (and it will get to the temperature of boiling water all by itself), and let it not call for heat when it doesn't need to (and it will cool down a bit between calls for heat). You don't have to monitor the temperature of a residential steam boiler.

Unless you are generating hot water from the steam boiler's water for some purpose (and I can't see you mentioning that in this thread) then you don't have to worry about how cold it gets.

WMno57

RTW said:

My service tech told me keeping it at least warm - 120 degrees - will prevent having issues with the chimney that could affect the liner is all I know.

Is your service tech from the oil company? Maybe he wants to sell you more oil.