Tarm low water cutoff?

[Bad Wolf]

Just had the building inspector in and the only thing wrong was I didn't have a low water cutoff installed. This is apparently fairly new code requirement in Connecticut. Where do I get one and how does it hook into a Tarm Excel 2000? I have a call into Tarm but haven't heard back yet.

I'm a little put out with Preston Trading post that they didn't mention this was a requirement and an addition control that I would need to buy.

Thanks

Greg H

 

[Nofossil]

That's a new one!

Low water cutoff makes sense for an oil boiler that starts automatically - you don't want it to start if there's not enough water (or pressure, more likely).

However, wood boilers are started by humans. To have the desired effect, the low water cutoff would have to stop you from lighting a fire. Once the fire is lit, I really don't think you want to remove power.

I may be wrong, but this seems like yet another example of codes leading to increased expense, no benefit, and possibly a less safe installation.

It *might* be a good idea to have some sort of warning light that illuminates if there is any condition that might suggest that you don't want to light a fire - low water pressure, no heat demand, inadequate draft, excessive beer consumption, and so on.

 

[mysticfalcon]

That's a new one!

Low water cutoff makes sense for an oil boiler that starts automatically - you don't want it to start if there's not enough water (or pressure, more likely).

However, wood boilers are started by humans. To have the desired effect, the low water cutoff would have to stop you from lighting a fire. Once the fire is lit, I really don't think you want to remove power.

I may be wrong, but this seems like yet another example of codes leading to increased expense, no benefit, and possibly a less safe installation.

It *might* be a good idea to have some sort of warning light that illuminates if there is any condition that might suggest that you don't want to light a fire - low water pressure, no heat demand, inadequate draft, excessive beer consumption, and so on.

Speaking of the beer consumption last weekend I got home from going out and I was a little bit hot in the head and cold in the house. Well I woke up the next AM and it was cold in the house and I thought I remembered building a fire when I got home. Well I went downstairs and there was the boiler shut up with a layer of newspaper, some kindling and some wood. Just waiting for a match. Apparently the night before I knew that I would be to hungover to build a fire in the AM.

 

[Bad Wolf]

Actually the Tarm Excel series is a dual fuel unit with an oil burner for backup, so it could come on automatically.

I'm guessing I install some kind of a sensor in one of the many extra tapping's.

Greg H

Hey Larry D you just installed an Excel didn't you? What did you do?

 

[pybyr]

That's a new one!

Low water cutoff makes sense for an oil boiler that starts automatically - you don't want it to start if there's not enough water (or pressure, more likely).

However, wood boilers are started by humans. To have the desired effect, the low water cutoff would have to stop you from lighting a fire. Once the fire is lit, I really don't think you want to remove power.

I may be wrong, but this seems like yet another example of codes leading to increased expense, no benefit, and possibly a less safe installation.

It *might* be a good idea to have some sort of warning light that illuminates if there is any condition that might suggest that you don't want to light a fire - low water pressure, no heat demand, inadequate draft, excessive beer consumption, and so on.

Speaking of the beer consumption last weekend I got home from going out and I was a little bit hot in the head and cold in the house. Well I woke up the next AM and it was cold in the house and I thought I remembered building a fire when I got home. Well I went downstairs and there was the boiler shut up with a layer of newspaper, some kindling and some wood. Just waiting for a match. Apparently the night before I knew that I would be to hungover to build a fire in the AM.

Good one Mysticfalcon- probably most of us have a story or two like that in our past. By the way, for all I know, I've bumped into you while raiding the bins at Granite Group/ Capital Plumbing, but never would've known it. Drop me a PM so that I can at least know who you are and say hello if we're both there.

 

[pybyr]

That's a new one!

Low water cutoff makes sense for an oil boiler that starts automatically - you don't want it to start if there's not enough water (or pressure, more likely).

However, wood boilers are started by humans. To have the desired effect, the low water cutoff would have to stop you from lighting a fire. Once the fire is lit, I really don't think you want to remove power.

I may be wrong, but this seems like yet another example of codes leading to increased expense, no benefit, and possibly a less safe installation.

It *might* be a good idea to have some sort of warning light that illuminates if there is any condition that might suggest that you don't want to light a fire - low water pressure, no heat demand, inadequate draft, excessive beer consumption, and so on.

I rarely question the esteemed NoFo, whose technical training and experience in general, and experience with gasification in particular, vastly exceed mine.

But- if your boiler is running low on water, and/ or steam or air is getting into your circulators, why would you want to keep feeding air to stoke the gasification process? if a leak starts, and the fans are cut off, at least there is a hope that the fire will die down before melting the firebox.

if a leak starts and the fans keep running, well-- let's just say that I am heavily influenced by an experience I had in very the early 90s when I was renting a place that had an early huge tarm, and a steam pocket occurred around the high limit aquastat, causing it to fail to cut the thing off even though it had had some sort of malfunction on the water feed (because the steam failed to conduct the heat to the sensor as well as water would have).

I came home after a night of carousing to feed it its bedtime snack of logs, and walked into a utility room that looked like some kind of meltdown- water running across the floor, steam everywhere, and boiler gaskets that had (thankfully) blown sideways out of their seams and let go before something else did

I'd already bought and begun to install a low water cutoff even before someone (forget if it was Joe or Hot Rod) recommended one in the other thread where I discuss trying hose barb fittings with 1.25 inch pex

I'm not arguing that a low water cut off is essential if you don't have one- just saying that for me, I'll sleep better knowing that the combustion will hopefully be slowed if there's a leak

 

[LarryD]

Greg,

PM sent

LD

 

[Stickler]

Greg,

I have had a Tarm multifuel since 1978 with a low water cutoff..Safgard by Hydrolevel. It is installed just up from the hot water feed in the pipe. Shuts off the boiler when the water drops down. It worked once when we were on an extended vacation and some a slow leak caused the cutoff to do its thing. It was discovered by a friend checking the house. Two pieces of good news, the house didn't freeze and the boiler was protected.

It only has to work once....

SS

 

[Nofossil]

But- if your boiler is running low on water, and/ or steam or air is getting into your circulators, why would you want to keep feeding air to stoke the gasification process? if a leak starts, and the fans are cut off, at least there is a hope that the fire will die down before melting the firebox.

That's a GREAT idea, although it would require getting into the wiring at a more intimate level - on the EKO at least, it would require a relay, since removing power to the controller would also kill the circ. Perhaps if there are low level cutoffs that are just contacts it wouldn't be so bad - the one that I've seen provides power rather than contact closure.

I've seen low water cutoffs on steam boilers, but hot water boilers seem to be more likely to have low pressure cutoffs. My concern is that low pressure (not low water) isn't sufficient reason to kill the circulator, since it's virtually guaranteed to cause a boilover.

 

[pybyr]

But- if your boiler is running low on water, and/ or steam or air is getting into your circulators, why would you want to keep feeding air to stoke the gasification process? if a leak starts, and the fans are cut off, at least there is a hope that the fire will die down before melting the firebox.

That's a GREAT idea, although it would require getting into the wiring at a more intimate level - on the EKO at least, it would require a relay, since removing power to the controller would also kill the circ. Perhaps if there are low level cutoffs that are just contacts it wouldn't be so bad - the one that I've seen provides power rather than contact closure.

I've seen low water cutoffs on steam boilers, but hot water boilers seem to be more likely to have low pressure cutoffs. My concern is that low pressure (not low water) isn't sufficient reason to kill the circulator, since it's virtually guaranteed to cause a boilover.

And you are giving me even better ideas (and I'd expect no less here in the Boiler Room). I've already hacked the back panel of my Econoburn 150 in half with a cutoff wheel to make it way easier to do the seasonal scrub of the fire tubes- so- why should I stop now

[queue the mad scientist Bu Wah Ha Ha sound effects ].

I should wire up my Safeguard 550 low water control so that it kills power to the fan, without killing power to the circs or any controllers that I eventually figure out for this set O' stuff.

The Ecoboburn's PLC/PID and relay-based systems will be much more adaptable to such a hack than- as far as I can tell- the other makes

 

[BrownianHeatingTech]

If the water level is low enough to shut down a low-water cutoff, then there's no reason for a circ to be running - it won't be pumping anything.

Joe

 

[Vtgent49]

Isn't it normal to have the water continously connected to the house supply? Mine is, and it goes thru a back-flow preventer and pressure reducer. How could there be low water?

 

[BrownianHeatingTech]

Isn't it normal to have the water continously connected to the house supply? Mine is, and it goes thru a back-flow preventer and pressure reducer. How could there be low water?

Even when operating correctly, the boiler feed doesn't flow a low of water, so a large burst pipe could easily allow more water out than the feed can replace.

Add some sediment, and the feed can be flowing little, or even nothing. Or it could fail for other reasons. Even a tiny leak could drain the system, if the feed was totally dead...

Joe