Taco 007 and BG 10734

tossup20 · February 2

Hi all, I decided to ask the long tail on this site since I see a number of refs to the equipment in the subject.

The equip is from 2008. Mostly flawless except for this sitch which has been happening for years pretty darn consistently.

Winter comes, heating calls, but this zone (in a half basement HW baseboard) wasn't used daily and could drop to 54deg. But earlier in the season calling heat in the zone would be fine for a few weeks. Then, say mid january, no heat, it seems when the temps got really cold (say mot above freezing for a few days). It might fail a few days and always seemed to recover once the cold snap broke. All other zones/thermostats are fine.

This year,in New York, its been colder, consistently, than it has been in years. But I also use the zone alot more often now, essentially daily, and set the therm to 65-6. No probs until last night. A difference, I hadn't used the zone in 4 days. The temp dropped close to 50. Called and got no response.

When this first happened, years ago, some one suggested tapping the BG to unstick it. I don't remember I think it did work then, but not since. Now Its just wait for a little warmer outside temps.

Airlocked doesn't seem to fit: I never hear gurgling, only the expansion of the baseboard as it heats.

BG opens and closes—and will dribble if left too open. The one next to it I wouldnt want to touch: packing area is coated with rust.

yes the taco is very hot, pipes too, above and below, but no hotter than the other two tacos (working fine) on the same supply pipe. the BG pipes can be hot — but the BG is above the boiler in close proximity, that line then drops to the floor and leaves the boiler room (its cold)

frozen h20 doesn't seem a prob — there's no flood.

Its been years since I got a pro mechanical opinion. But no equipment was changed and the symptom remains.

Two days ago, we lost the boiler— clogged nozzle. Regular service effort and all good. We've been consuming like nobody's business this season. The unusual cold along with advancing years the thermostat in common areas is a few degrees higher for much of the day than in the past.

The boiler will lock out. Been fine this season, until this AM. I forgot to plug in the frostking line outside. Few minutes with a hair dryer and fine. Why it chose last night (after weeks of constant below freezing temps I don't know).

Anybody have any ideas? Its the intermittent, practically predictable, nature of it that makes me twitch.

Thanks for, and hope you enjoyed, reading.

hot_rod · February 2

there is a lever on top of the red BG valves, turn it counter clockwise to manually open that check valve.

For the pumps, check for voltage at the pump. Also the valve below the pump, slowly start closing that. If the pump is flowing you will get some hissing noise as the valve shuts down flow.

the pump should be just a bit warmer than the pipe it connects. It should never be scalding hot, indicating it is locked up.

HVACNUT · February 2

Have you tried to purge the loop? I bet you get no more than a few ounces. You say its fine in milder weather, so I'd say the loop is freezing somewhere. Luckily not enough to burst.

Find the draft, seal it, and insulate the pipe in that location.

tossup20 · February 5

Hi all and thanks for your ideas.

I try the therm every morning (it has been a little warmer but outside temps remain below freezing). No response. But! the thermostat said Batt Lo. I Changed the batteries when this problem started (earlie this week this season) So they shouldn't be "lo". Question that (like partially freezing pipes) makes me cock my head at an angle: It is a vintage thermostat (at least 16 years and possibly before my time here (so 24+). I know the therm is calling — I can hear it click, the taco and pipes start cool but get too hot to touch. Is it possible the thermostat can call, but be failing (for years?? — ahh just plain defective maybe) and interfere with the operation of the taco (or other mechanicals)? There is an Argo control board and the taco is wired through that (along with the other 3 therms. thanks.

here is my earlier stream of consciousness. Writing helps me organize thoughts and ideas, its easier to do if there's an audience.

Yeah, after laying out the history and symptoms I started to think some "minor" freeze is the culprit. And thought about locations where it could happen. First one was in the raised hearth of the fireplace. line runs under that brick and mortar. the fireplace chimney is stuffed with insulation, but that doesn't mean its got no drafts in its walls. Hearth accessible by loose blustone caps. Its a mid-60s slab/foundation near a corner that doesn't get cold north wind but not much sun either. Other possibility is a modern section that avoids two sliders in another corner (which does receive upslope winter winds — Lotsa wind, little sun. Pipe runs up one wall 90's across the ceiling to the other wall comes down and continues. That section was foam insul;ated — and

EdTheHeaterMan · February 5

Just a thought. Is there a part of the problem loop that is close to an outside vent in a crawlspace? I had an electrician customer that tried every electrical way possible to solve a frozen pipe issue on one zone that has a pipe that dropped below the floor into the crawlspace next to a crawlspace event. I used a heat gun to thaw the pipe and the heat flowed once the ice block was removed.

Since it only happens after a prolonged off or standby time, and when the temperature is low. I think that ice blockage might be a possibility.

As far as the frost king not being plugged in… Is that for the fuel line?

tossup20 · February 7

Well, here you go. I was out today, noticed the car was consistently saying it was 35deg. Balmy. Got home decided to try the zone one more time. Low and Bee Old, its thawed out and circulating.

So there's a popsicle just big enough to resist 20psi, but not enough to burst the copper.

My money is on the fireplace area. Just stony enough to transfer cold and draughty enough to thaw quickly. Problem is, since the FP is so inefficient, I put a big rack of Vinyl records on top of the hearth. Before I placed that there I thought I'd seen the copper under the bluestone (the hearth is raised off the slab). But after looking at the baseboard I find it dives into the slab in the corner runs, along the wall, "under" the fireplace, along the wall again and finally surfaces the slab to connect with the next section of baseboard.

Wouldn't mind digging up the slab (its a damp corner with mid-60s slab design) and insulating everything but I also found the old lino on the slab has asbestos.

EdTheHeaterMan · February 7

@tossup20 said: "So there's a popsicle just big enough to resist 20psi, but not enough to burst the copper."

Actually, your circulator pump does not make a 20 PSI difference in pressure from the inlet to the outlet. 20 PSI might be the static pressure of the water at the boiler. Your city water pressure might be 50 to 80 PSI and the fill valve should only allow water to enter the closed system if the pressure drops below 15 PSI.

The Taco 007 pump for example, might only have a difference in pressure from the inlet to the outlet of about 3.5 PSI difference if your system curve and pump curve intersect at about 8 Ft head. Which would be for a boiler that is producing about 50,000 to 100,000 BTU per hour NET output. So not much of an icicle needed to stop the flow. A slushy mix of ice and water can be something that small pump cant push thru.

Taco 007 and BG 10734

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