Intermittent small levels of CO

leegej

I’m getting intermittent low levels of CO, never much above 50ppm. The only gas appliance running at this point is the hot water heater. It is at least 10 years old, natural vent up an old chimney. The chimney is in rough shape, but it is 100% clear. Any input on what would cause such random low levels?

I’m prepared to replace it, but can I trust venting a new one up the same chimney considering I’m having problems with that set up? Or should I spend the extra cash on a forced vent?

STEVEusaPA

Draft problems are pretty common when you orphan a chimney and leave it severely oversized for just a water heater.
You can either get a Level II chimney inspection and if the structure of the chimney is sound, have a properly sized liner pulled, or switch to forced vent.
Also keep in mind 50 ppm on a gas fired water heater with a vent hood is pretty common. NOT good, but common. If you stick a low level CO detector near a draft hood on a good chimney, you would get CO from flue gas spillage. In one case, my monitor was spiking up to 250 ppm CO on a windy day while I was cleaning an oil fired boiler. Shocker to me that it would be that high.

Zman

To be clear, where are you measuring the CO? In the vent with a combustion analyzer are in the space?

leegej

It’s an old farmhouse, so the chimney is over 100 years old. Certainly not going to put a penny into inspecting and repairing the chimney. I was planning to put an indirect in after I got my boiler up and running for my radiant. Indirect tanks are not cheap tho! Is it safe to assume an indirect tank should last longer than a gas fired hot water heater?

Zman

A quality indirect will last longer and when connected to your mod/con boiler will run much more efficiently. I would not recommend the triangle tube indirect.

Zman

50 ppm measured in the living space is not OK, even intermittently!

STEVEusaPA

You have a 100 year old, unlined chimney inspected for integrity. Could be dangerously close to collapsing.
Isn’t that worth a few hundred bucks?

leegej

I’m getting 50ppm million on the meter in my bedroom on the first level, hot water heater is in the basement. Have been sleeping with the windows open! I agree inspect the chimney for structural integrity, I was referring to not spending money on a liner. I know the chimney is in sad shape and intend to remove it when we re roof the house.

My boiler is a triangle tube prestige solo 110, what’s your reasoning against the triangle tube indirect? And what are peoples recommendations for an indirect? Thinking 60 gallon would be plenty. I’m a firm believer in buy once cry once, but there’s a baby on the way so I gotta be careful with the checkbook too.

Zman

Stop the madness and turn the water heater off immediately. There is nothing OK about 50 ppm in a bedroom!
I think the Triangle Tube Indirects are unnecessarily complicated and almost impossible to flush out. I stay clear of Amtrol as well.
There are tons of simple stainless indirects with generously sized coils. HTP, Heat flo, Lochinvar are all good options.
Most homes can get by with a 40 gallon. If you have large tubs to fill, you might want to go with a 60 gallon model.

Bob Harper

Opening your windows may be causing CO spillage. 50ppm read by a UL listed alarm in a bedroom means it could be much higher elsewhere, such as upstairs. Before you breathe another minute in this home much less bring a child in you need to know when and where it is spilling, why the WH is making so much CO, and let this info. guide your decision. If combustion analysis proves the WH is burning improperly it will also show the reason. Some things, such as simple cleaning might solve it or you may need to shut it down right now. All chimneys have required liners since 1927. An unlined flue makes your house uninhabitable by legal standards. Either reline it with an atmospherically vented WH or pick a non-chimney option. Boilers are better at cooking water than water heaters. A 36-40 gallon indirect tank would suffice for most households of 4-5.
Regardless, you need a low level unlisted CO monitor within 15 LF of any sleeping room.

GW

50 ppm in the living space, in an old house ? Wow you’ve got issues. Get it fixed

leegej

Water heater is shut down, I have a superstor ultra 60 gallon that is newer than I thought. Can anyone interpret this date code? It’s been empty for a couple years. If I got it de limed what’s everyone’s opinion on installing something 10ish years old that hasn’t been used for a couple years?

mattmia2

So look at your water chemistry, stainless indirects don't like water with high sodium levels. You may need a larger tank than you think depending on your incoming water temp, how quickly the boiler gets up to temp and how large the boiler is. There is a table in the superstore manual giving first draw capacity. Note your income water temp and the capacity of the boiler when reading that chart.

Larry Weingarten

Hello, I tried finding the age of your Superstore online, but no luck. A call to HTP couldn't hurt. If they follow convention, the K14 in the serial number would represent month and year which would be late in 2014 that it was made. I might look on the tank for other clues like an ANSI date (which is good within a three year range or date on the relief valve.

Should you go with a heater that needs venting, might running "B" vent down the chimney work? Aside from that, I'd look for anything that could imbalance things, like a range hood that could create negative pressure at the heater.

Yours, Larry

leegej

There’s nothing else hooked to the chimney, the water heater is the only thing left that is natural vent. Inspection camera shows a clear chimney, but I’m fairly certain it’s unlined and pretty deteriorated. Gonna have to look into removing it ASAP. Triangle tube prestige solo 110 boiler. I believe it’s about 90k btu supplying radiant, isn’t running yet. I thought I had time to get everything finalized and running before the next heating season. So I’m working at getting everything soldered in and water hooked up. Tomorrow I’ll get that superstore pulled out of our old milk house and put some vinegar in to de lime, then I’ll work at getting it installed. Current hot water heater is 36k btu, so a 60 gallon indirect hooked to this boiler should be over kill for me and my wife, and baby very soon.

This triangle tube boiler has a boiler supply, boiler return, and a DHW coming out of it. Would I simply hook my supply to the indirect to the DHW tap on the boiler using a zone valve, then put the return on the return line between the boiler and the hydraulic separator going to the radiant? And use an isolation relay to turn off the 3 radiant zone pumps when there’s a DHW call? That way I use the pump inside the boiler as my indirect DHW circulator?

Big Ed_4

Do you have a gas stove ?

leegej

No, switched to a flat top electric and we hate it. Can’t wait to go back to a gas stove! We do have a gas drier tho. I turned the gas off to the clothes drier for 10 days and it didn’t make any difference. Only has appliance on was the hot water heater.

Steamhead

Now that you've shut the water heater down, keep monitoring your CO just to be sure. There may be another source.........

icy78

It is also possible that you have too much draft. This would cause spillage out of the draft Hood also.
The first step would be to measure the draft with a very accurate gauge above the draft hood of the water heater. If you have a positive pressure than the rest of the house is becoming the chimney and the chimney is becoming part of the make-up air and no matter what you do to the chimney as far as liners or whatever it isn't going to change that. It's a whole house issue and has to be dressed as a whole house issue. Often the leakiest homes are the worst for correct chimney draft.
You may also have a sooted water heater due to incorrect Drafting and are now noticing the effects of that.
If the above is true, correcting the misdirection of airflow within the house and adding a barometric damper and spill switch would be the course of action here. Or you get away from it all and install a high efficiency water heater.

I should amend this by saying that chimney repair or a liner would very well add more resistance to air movement so in one way or another could or would affect draft direction. It would change the dynamic of air movement within the home possibly but not necessarily in a corrective manner.

Zman

He has a 100 year old chimney and a beat up old water heater spewing CO.
He also has a triangle tube boiler all ready for an indirect. I would not waste a second diagnosing this. Simply add the indirect to the existing boiler and be done with it.

leegej

Thanks Zman, I agree. Made my day and my checkbooks day when I discovered I already had an indirect I could put in. I had thought it was 20+ years old, but that’s the free heater tank for the milk cooler.

As I said before, the triangle tube has a DHW output. Do I hook into that to supply the indirect, and plumb the return into the return line between the boiler and hydraulic separator? Then use an isolation relay to turn off all heating circ pumps during a DHW call, and use a zone valve on the DHW supply line. Doing it this way should let me use the boilers internal circ pump correct?

captainco

How long have you lived in the house? How old is the CO alarm?

There are other things beside CO that can cause alarms to read. Hydrogen sulfide from charging lead acid batteries does a great job at that. Ethylene and Methylene Chlorides (heavy duty cleaners), Acetylene gas just to mention a few. Also certain radio frequency (RFI) can cause sporadic readings.

Is it the water heater or is that just a guess? The only way to identify if the water heater is a problem is a proper combustion analysis.

Opening a window upstairs could cause the water heater not to vent.

Zman

leegej said:

Thanks Zman, I agree. Made my day and my checkbooks day when I discovered I already had an indirect I could put in. I had thought it was 20+ years old, but that’s the free heater tank for the milk cooler.



As I said before, the triangle tube has a DHW output. Do I hook into that to supply the indirect, and plumb the return into the return line between the boiler and hydraulic separator? Then use an isolation relay to turn off all heating circ pumps during a DHW call, and use a zone valve on the DHW supply line. Doing it this way should let me use the boilers internal circ pump correct?

Which generation Triangle Tube boiler is it. How is your existing setup piped and controlled?
The bottom line is that boiler is capable of controlling all of this. It is usually easier to put the indirect on a separate circulator and set it for DHW priority. That way the radiant can run on outdoor reset without impacting the performance of the indirect. It becomes a 2 temp system. One for heat and the other for hot water indirect.
The Triangle Tube manual spells this out clearly.

mattmia2

leegej said:

I believe it’s about 90k btu supplying radiant, isn’t running yet. I thought I had time to get everything finalized and running before the next heating season. So I’m working at getting everything soldered in and water hooked up. Tomorrow I’ll get that superstore pulled out of our old milk house and put some vinegar in to de lime, then I’ll work at getting it installed. Current hot water heater is 36k btu, so a 60 gallon indirect hooked to this boiler should be over kill for me and my wife, and baby very soon.

Don't assume that will be ok just from the btu output. The dynamics of how an indirect heats are very different from that of a direct fired gas water heater. The direct fired water heater has the thermostat near they bottom of the tank so it senses the incoming cold water very quickly and it starts heating the water as soon as the burner lights. An indirect has the temp probe about half way up the tank so it takes longer for the cold water to reach that level and trigger a call. Once a call is triggered, the burner needs to go through an ignition cycle and heat the water in the boiler side before it starts transferring heat to the tank. This means that by the time the boiler starts heating the water and develops full output, cold water has been entering the tank for ~5 minutes or so. If you look at the first draw tables in the HTP manual it calls for something like a 200,000 btu/hr boiler output to get the values in the table for the 60 gallon tank. It is relying on the high output of the boiler to make up for the lag between when the demand starts and when the boiler actually starts heating the water.

leegej

First, I pulled the burner out of the hot water heater and cleaned it and the chamber up. It’s currently running and I didn’t have any CO issues over night. I still want to get this indirect running sooner than later, I can’t trust that hot water heater anymore.

Triangle Tube Prestige Solo 110 was installed in our parlor in 2013, along with this 60 gallon indirect tank. It supplied our milking parlor with hot water. I’m now repurposing it for my house.

I have 3 zones and each has its own Grundfos alpha pump. 2 zones are low temp infloor radiant. One zone is “high” temp panel radiators on the 2nd story sized for 140 degree water. Boiler will be outdoor reset set for the panel radiators, then a taco I series 3 way mix valve also running outdoor reset to mix down for the 2 low temp zones.

Nothing is wired yet, this hot water heater issue snuck up on me. I read Modern Hydronic Heating last fall and winter and had a whole game plan, but that was more than 6 months and a lot of remodeling ago and my slate is currently blank as far as wiring and controls.

High temp panel rads circuit I was going to set the pump to constant pressure and run off the panel rads TRVs. The two low temp infloor zones I don’t recall my game plan there.

HomerJSmith

leegej, you are using an off the shelf CO detector? Buy another one, maybe from Costco, and compare the readings. They are great as a warning device, but professionals use calibrated CO meters. Yours may be not giving the proper reading.

Many fire departments have calibrated meters and will test for you.

CO is accumulative and a time factor as to poisoning. It is PPM + the time of exposure that's lethal.

leegej

Yes I understand CO is PPM over time. We got two brand new ones when it tripped the old ones. I brought my gas meter home from work and calibrated it and I never saw higher than 2 ppm while the home detectors were reading 50 ppm.

Zman

leegej

Thanks Zman, that’s easy enough. Just seems odd to me that the boiler circulators pumps it straight into the DHW circulator.

Zman

They both should have check valves.

leegej

I’m making a purchase of the circulator, aqua stat, relay control, ODR sensor for the boiler. Got to thinking. When I removed this boiler, it was only used for DHW and therefore only hooked to an aqua stat. I’m low using it for heating and DHW. Do I need some sort of sensor for the boiler sensing supply/return? I’ve gone through the triangle tube manual and can’t seem to find an answer.

Zman

You don't need a separate system sensor. The one in the boiler will take care of it.

leegej

Thanks Zman! That’s what I was thinking considering I couldn’t find anything in the manual about a separate sensor!

Joe_Dunham

Google -"re-burn" of carbon monoxide. Interesting. a stove top generates 0ppm, until you put a pot on it and an oven can generate as much as 800 ppm. but you should read about re-burn

leegej

Using a taco relay control, I’ll have my radiator zone alpha pump hard wired and use a current sensing switch to turn on the boiler. The two radiant zones will be through the taco relay control each with its own thermostat. If I wire my indirect DHW pump through the taco relay control and use the priority setting, will the boiler know to ramp up to high temp and not run off the boiler ODR sensor?

Zman

The boiler needs to control both circs.
I think you may need to add a relay or 2 in order to get this to work with your CT switch.
Can you post a drawing of your present wiring?

Zman

It is probably easiest to put a DPDT relay on the indirect so that the alpha turns off when the dhw turns on. From there you can let the boiler do it's normal outdoor reset, DHW priority.

leegej

The triangle tube boiler has 4 line voltage terminals for circulators, 2 thermostat inputs, and 1 DHW aqua stat input, but it’s not clear if I can configure them to do what I need... I need 2 pumps run of thermostats, 1 DHW priority pump, plus the internal boiler circulator.

leegej

Photo of the terminals on the boiler.

Zman

The way you are piped creates a bit of a control challenge.
If you use a DPDT relay with a 120 volt coil https://www.supplyhouse.com/Tekmar-004-Relay-120-V-ac-coil-7924000-p?gclid=CjwKCAjw8pH3BRAXEiwA1pvMsTml-PGoBIepvmBaBbuZ5di1q1ErNdbFNgzQZYiWPSpGX2Of4JAQmRoCYwUQAvD_BwE and wire it to the DHW circ terminals in the boiler you should be able to solve this. The power to the circs on taco controller would pass through one side of the relay connected to "C" and "N/C" this provides power to the controller when ever there is no call for DHW. The Power to the DHW circ would attach to the other side of the relay connected to "C" and "N/O".
This setup creates an "either/or" logic with a simple relay.