OWB circulator pump - 24/7 or on demand?

[Canton]

Just curious - do you guys run your circulator pumps 24/7 or on demand? Advantages / dis-advantages? thoughts?

Brand new to the OWB thing. Set mine up for 24/7 through the water to air exchanger in my air handler and use the T-stat to turn the fan on and off. Been working fine, but since I never tried cycling the pump with the T-stat, I was wondering if there was any reason to try it.

Thanks.....

 

[jh35]

Just curious - do you guys run your circulator pumps 24/7 or on demand? Advantages / dis-advantages? thoughts?

Brand new to the OWB thing. Set mine up for 24/7 through the water to air exchanger in my air handler and use the T-stat to turn the fan on and off. Been working fine, but since I never tried cycling the pump with the T-stat, I was wondering if there was any reason to try it.

Thanks.....

I'm new to it myself last fall but several friends and family have a Heatmor so I was familiar when I bought mine. We all run pumps 24/7 during heating season. One of the wife's cousins has ran his pump 24/7/365 for 8 years now with no issues, and it isn't firing in the warm season.

OK the electrical cost would be higher, but I'm using a sidearm for DHW and its needs to circulate more than just when the house calls for heat. Dad burns all year for the DHW so his pump does not shut off either.

I'm interested to hear what other people do also as I'm not entirely set in stone on any way of thinking.

The pumps are not all that strong anyway ( at least mine isn't) in fact when FIL's was brand new it was locked and I had to take it off to give it a nudge. 5th winter on that one now with no problems.

What owb do you have?

Jeff

EDIT: I see your sig now

 

[Canton]

I have the "less than popular" Shaver boiler. All I can say is so far, it's worked flawlessly. I took the recommendations from this site that shaver didn't incorporate into their latest model and it's worked exactly like I expected it to. I'm planning on using it year round for my domestic hot water, but since that has its own pump that runs to a coil in the boiler, there's no need to circulate through the house in the summer.

 

[phantomblack]

Mine runs 24/7 during the heating season. No problems with the pump when the boiler is running, and I do not do something stupid to cause the pump to boil over and cavitate the pump. I have only had problems on "start up" after sitting for the summer and the early fall where the pump is "stuck".

That being said, I was running a taco 009 and now have changed pumps to the B&G NRF 25 at the beginning of this season so that it is a common pump with the zone pumps for my in-floor radiant heating system. The B&G pumps that I have in the house for zone pumps have never had an issue while sitting for a summer and early fall. I still have two 009's for a backup pumps, but it was a little oversized for my application and a little hard on the electric bill. The NRF 25 on speed two uses half the amperage in my application that the 009 used, and is almost silent while it is running where as the 009 sounded like a bumble bee all the time.

 

[Encore]

Mine is on demand but I can quickly change it to full time with a small wire. I do that when its super cold like it has been to prevent any chance of the line freezing where they come to the stove from the ground.

I tend to use less wood when it's only on demand. But that's about the only benefit.

 

[Woodomaker]

CB unit. 24/7

 

[Poston5]

I am a fan of on demand for this reason. If you are losing 3 degrees from the stove to the house while the pump is running, why run the pump if you dont need to. Keep the water in the water jacket and it maintains 180+/- and you are not losing the temp while it travels to the house. On the other hand if you are heating DHW in the house you need to circulate 24/7.

 

[Canton]

I am a fan of on demand for this reason. If you are losing 3 degrees from the stove to the house while the pump is running, why run the pump if you dont need to. Keep the water in the water jacket and it maintains 180+/- and you are not losing the temp while it travels to the house. On the other hand if you are heating DHW in the house you need to circulate 24/7.

I have to agree with this for the most part. I guess you have to calcuate in the loss to re-heat the lines and heat exchanger once the pump runs, and then the wear and tear on the pump. I'm guessing unless you have significant loss in your line set, it's 6 of one / half dozen of the other.

My domestic is on a seprate loop with the coil in stove, so that's a non-issue.

 

[memory]

We have a CB 6048 with 2 water heaters hooked up to it and run the pump 24/7. We also burn wood 365 days a year.

 

[greendohn]

24/7 during the heating season, shut it down in the spring/summer. I've got the idea that on/off requires some kind of control (? solenoid?) to trigger the on/off, with the 24/7 I have one less thing to worry about, the pump always has power, it's either running or it's broke.
I could be wrong,,,,it's happened before.

 

[Guswhit]

My CB 5036 runs 24/7-365.
My buddy has a CB 6048 that he heats 2 DHW 2 out buildings and his house. He is also OCD and anal about things. After his first winter running this way he put a bypass valves on all of the heat exchangers that activate when the thermostats call for heat. He says he saves wood this way, looks like more electric crap that could go wrong to me??????????

 

[Iska3]

We have a gutted forced air furnace connected to the OWB for our main heat so I run our pumps 24/7. When the stat does not call for heat, there is still a lot of gravity/ convection heat being pulled from the exchanger and going up our vents. I find I have a longer off time between cycles on the blower fan. It cost a lot less to run the pumps than the furnace fan. I also heat our hot water with a plate exchanger 365 so I’ll by pass the furnace in the summer time. The pump for the furnace in the garage / craft room runs 24/7 but I turn off the blower unless we are working out there.

 

[scag52]

I run mine on demand . No need to run when no call for heat .

 

[Storm56]

I run mine 24/7 during the heating season and a couple of times during the summer for a few minutes to keep them free. I also heat my DHW and Spa from the unit, so the pumps need to be running for them also. Side benefit is it keeps my basement dry and at about a 65 degree temp. Also when my air handler kicks on I have instant heat instead of blowing cold air until the heat exchanger heats up.

 

[uglydukwling]

I shut my pump off for the summer, but in the winter I have to let it run constantly.If I have a fire going, even without the fan, I get hot spots in the boiler if the water isn't circulating, and the water will boil. ( Maybe "boiler" isn't a good name, because we don't want the water to actually boil.)

I found this out when the ground fault tripped and shut down the pump and I didn't notice for an hour or so. When we have a power outage, I have to go out and manually shut off the air to the firebox. I also shut it off at night and if I'm not home, just in case.

I've been thinking that I should set up an automatic air shut-off, so if the pump loses power, the air supply will also close, but I haven't been able to find a suitable solenoid. I suppose this might be a good time to ask if anyone knows of one ( a part number would be nice).
It should have a 2.5" stroke, normally extended, retract when energized, and operate on 120 V, AC so I don't need a power supply. Of course, I could probably adapt something that doesn't have all these specs, but it would be easier if I could find one that will work right out of the box.

 

[Stlshrk]

Ours is a gassification set up and I added the 750 gal strg tank. The pump from the tank to the house loop runs 24/7 during the winter. The pump from the heater to the strg tank only runs during a burn cycle. This allows us to burn full out without any idle time or smoldering/smoking up the joint. Then those BTU's are in the big tank and the house gets heated from that. We also do our dhw in the winter off of the house loop. It isn't worth burning only for the dhw in the summer, unless we upgrade and put in a hot tub. Then we would, of course, get to (have to :msp_thumbup: ) expand!

Cheers!

 

[Ed*L]

On my Heatmor it'll boil over if the pump's not running.....

Ed

 

[battlefordguy]

Great topic
I burn during the cold months (9-10 months/year) pump runs 24/7.
Aside from the DHW I feel there is a great heating benefit from the radiant heat from all the uninsulated pex loops in the house. Would this gain in heat balance off any extra wood saved from running a pump intermittently?
First grunfos pump lasted 5 years, however the boiler was overheated a couple times (owner ignorance)in the first few years of use.
I often wonder if - I increased the amount of radiant heating possibilities in the house ( more pex runs,radiant heaters,etcwhat effect could I realize in wood savings/ more improved btu management?

Currently the majority of heating occurs via water / air exchange thru a large rad in the furnace. With one base board heater, plus any radiant heat from the exposed pex lines.

 

[blackdogon57]

I run 2 taco 009's. One 24/7/365 and the other only during the winter. After reading this thread I checked the taco website. They say the draw is 1.4 amps on the 009. I calculated my cost to run one pump 24/7/365 is about $10 per month. Not bad considering the thousands I am saving per year.

 

[kennyl70]

heatmor and run it 24/7.....