Changing way circulators work? Aka What to do about Standby loss

I know these kinds of posts don't often get replies, but please take a look.

I am considering changing my main circulator loop pump to a multi-speed and running it constantly, along with one main zone. Let me know what you guys think or problems to watch out for?

We have KA6 with single large circulator loop that has each zone with closely spaced tees and individual circulators (IFC) using 2 zone controllers.

I had been considering some fancy control replacement that would satisfy heat calls in a zone, then designate one or more zones that were permitted to accept more heat one a low and slow basis to utilize the standby and post-firing heat in the boiler. Think of thermostat setting as a "Minimum" setpoint, maintained by calls for heat, and a "Coasting" setpoint allowing zone to passively surpass that point without a new call for heat- as long as the main loop and boiler were above minimum levels.

My timer cycles my boiler quite often for very short periods. I plan to work on this a bit, but it requires close supervision while changing to avoid out-fires.

Now it has occurred to me that I may be able to attain close to this quite simply and am look for opinions or potential problems.

If I change my main circulator pump to a 3 speed Taco and let it run at normal speed during calls for heat, and then add an on-pipe tstat to continue to run the pump at low speed as long as pipe temp is above xyz Degrees, and do the same with my one zone that always needs heat (big heat loss area) and would increase comfort at higher temps (but not wanting to throw $$ into lots of fuel for the higher temp).

I could add an additional thermostat in that zone with a NC relay that would open if its temp (considered Maximum temp) was reached.

What do you think?

A standard multi-speed circulator has a manual switch on it, and can't do what you have described (you manually select the speed you want). You are describing a variable speed circulator controlled by some sort of logic controller. I am not aware of anything off the shelf that does what you want.

You can get zone controls that have a post-purge feature, but unless you are having problems with your boiler overshooting the temperature setpoint after a heat call, I don't really see the value. If you are looking for a slow & steady flow of heat to a particular part of the house, you could probably setup a zone to allow gravity circulation. That would be cheap & reliable.

Rob R. wrote: ↑

Sun. Sep. 26, 2021 5:13 pm

A standard multi-speed circulator has a manual switch on it, and can't do what you have described (you manually select the speed you want). You are describing a variable speed circulator controlled by some sort of logic controller. I am not aware of anything off the shelf that does what you want.

You can get zone controls that have a post-purge feature, but unless you are having problems with your boiler overshooting the temperature setpoint after a heat call, I don't really see the value. If you are looking for a slow & steady flow of heat to a particular part of the house, you could probably setup a zone to allow gravity circulation. That would be cheap & reliable.

Thank you for your reply. I didn't realize the circulators were only manually switchable speeds, but that makes sense.

Maybe post-purging one way or another is the best answer anyways. I am looking at battery to inverter backup in between generator runnings and for short power outages, so shorter run times may be better.

Cool, you could tap your single speed circulator if you care to go “custom”.

Relays and motor speed controls can be arranged to get what you describe. Not talking any big expense here.

McGiever wrote: ↑

Tue. Sep. 28, 2021 10:27 am

Cool, you could tap your single speed circulator if you care to go “custom”.

Relays and motor speed controls can be arranged to get what you describe. Not talking any big expense here.

Now there is an idea

I am considering changing a few things so my oil boiler can join or take over the heating if needed. It is piped in but I never finished setting it all up to be easy (for someone other than me). It wasn't a priority.

Well, we spent the better part of the past 3 years with friends and neighbors filling my coal hopper, changing a failed pump, etc while I was down. I couldn't even go say hi while they were doing it. On good days I could tap and wave out the window.

We've also had quite a bit more power outages and for longer stretches. 14hrs a few weeks ago.

Lessons learned.

I'm fortunate enough to have recovered enough for light things, so hoping to rectify these shortcomings.

Hoping to tweak it to be comfortable, convenient, reliable, and reasonably fault tolerant.

I hope ya'll don't mind the forthcoming questions

Bring it on!!

We’re here for ya!

CoalisCoolxWarm wrote: ↑

Tue. Sep. 28, 2021 10:52 am

I am considering changing a few things so my oil boiler can join or take over the heating if needed. It is piped in but I never finished setting it all up to be easy (for someone other than me). It wasn't a priority.

If you are depending on others to run the system, I think getting the oil system setup for quick & easy switchover is a good idea. You can set things up to make it automatic, or you could label the valves/switches and write up a simple instruction card.

Also keep that thought (will someone else be able to figure this out) in the back of your mind if you start down the road of custom controls.

I would suggest if you are constantly circulating water you would cause a lot of short cycling which is inefficient. Plus you are moving water at lower temperatures increasing the amount of power required to move X BTU's from point A to point B. Then there is the wear and tear on the pump.

How much heat are you putting into areas you don't want? e.g. is your basement going to be 10 degrees warmer and you don't want it ten degrees warmer? Keep in mind that loss to ambient air is still heat in the house whther you slowly circulating it or idling, it just may not be where you want it most.

Heating systems are most efficient when ran for longer times spaced out, that is why thermostats have setbacks. Newer and more efficient boilers have no LO setting, of course you can't do that with a coal boiler.

Think of heat as a glass of water, it wants to go to where it's cold represented by an empty glass of water. What is the most efficient way to move it from the full glass to the empty glass? You may be losing some heat to ambient air but that doesn't mean it's necessarily most efficient to be slowly siphoning it off.

Look at wiring diagrams for other dual-fuel furnace/boilers. Switch-over controls already exist, then copy that to yours.

Keystoker comes to mind for dual-fuel wiring.

A handy available hand drawn wiring diagram covers any mysteries as to wiring modification.

Thanks for the replies.

Some things I know about my heat efficiency...

Our living room is hard to heat and temps of 68F-70F are no longer comfortable, more like 72F-75F. But a tstat setting at 75F burns a lot more coal. I think we could set it at 72F and let the extra heat go into that space to stay between 72F-75F.

The basement where the boiler is located stays 65F-68F without a zone running due to heat loss. Normally that is okay, but I'd trade 5 degrees from there to the living room.

Our timer on the KA6 runs a lot. It stays lit most of the time, so the boiler stays hot mostly, even with no calls for heat. I think we could do better with fewer timer cycles (possibly even for the same length or maybe longer). But longer will make more standby loss when no calls for heat.

I believe I can add a flame sensor and an inspection port on the door to detect flame level. If I can manage to get it adjusted so it "accepts" an idle flame but triggers a timed cycles (5 min? 10 min?) once it drops below a certain level, it may not need a timer cycle. With some tweaking or a second sensor, I can finally add an out-fire shutoff (that could trigger an email and visual alert and fail over to the oil boiler)

Our insulation is getting better, but we had a big detour in that work for a bit, so still some poor areas.

We are going to start heating the back section of the basement where the laundry room is located and convert the rest to office space. Block walls, uninsulated concrete floor. 2 walls 100% below ground, 1 against front basement area, one usually 3/4 below ground but currently excavated. Again, current prices have pushed back the plan to build a replacement block room on the exterior of this wall, with a new doorway.

The front and rear sections are going to be separated for heat and coal/ashes dust isolation.

I posted some time ago about insulating floor and adding in-floor radiant heat to this rear basement area. Well COVID price spikes moved that out of the picture for now. About 25ft x 25ft new area to be heated. Without heat zone running it stays about 60F, except in really cold weather. Before the recent door replacement and floor/rim joist rebuild, we had pipes near the partially exposed exterior wall freeze.

For those curious, the previous patio was sloped incorrectly and spent over 30yrs rotting away the adjoining non-treated rim joist and sill plate, which invited carpenter ants to finish off ends of several floor joists, next level's studs, and some edges of plywood flooring.

They were eradicated about 10-15 years ago, but we had to remove the concrete patio and do extensive repair and replace, while adding a header that never existed to the doorway. SUBSTANTIALLY better now, but only about 80% complete. I was working until midnight when I had to get up at 0330 am for major surgery. Didn't even have a functional bathroom on that floor, which we had to setup as a makeshift recovery room and sleeping area.

I have not made it back to the upstairs bedroom yet, but the IV poles are gone, the chemo and radiation are over, parts are reconnected and repaired and I'm not only walking again, but I do quite well even without a walker or cane.

I shared the reason for delays so you guys don't think I'm lazy and beyond hope and help, LOL.

I have asked some of these or related questions before. I have forgotten a number of things and didn't get to implement others. On a side note, it is both funny and saddening when I search for something on DuckDuckGo or Google and the FIRST hit comes from this site and MY post- like flame sensor post of mine from 2016. LOL.

So there it is. We can laugh about it together and see how we can rework and tweak this system of ours for my girls.