Is there a set limit of CO that you can shut down a furnace from the TSSA. I know that on boilers there is the 100parts per million. Get it lower or shut it down on natural draft boilers equipped with a draft hood. Why I ask is we are told that up to 400ppmCO is ok and then we are told 100ppmCO. I never like to see it over 50ppmCO. I had one the other day that another tech shut down and they sent me out to check and I found the CO reading to be over 200ppmCO on a Lennox Whisper. I took the burners out and cleaned them and then re-did the reading and I came out with 2ppmCO big difference.
I always like to check and clean the burners and check the gas pressure to see if the furnace is over fired or under fired because that will give off high CO readings. I would just like to know for sure if there is a limit of CO. Thanks
Yes, Director's Order FS-072-06-R1 (http://hvactechgroup.com/files/order/FS07206.pdf) stated a natural draft boiler must have 100ppm of CO or lower in the flue. This order is actually expired, but they will probably be re-issuing it for the winter.
The GSW Superflue Advisory (http://hvactechgroup.com/files/gsw.pdf) stated you could have up to 400ppm CO in the flue. Given that these water heaters are installed with ABS venting, 400ppm could be very dangerous should the venting crack. This is probably one reason for making System 636 the new standard for venting.
The general rule of thumb is 50ppm, like you said, however it's not actually a part of the gas code or any TSSA advisory/order that I am aware of.
Alot of Techs check for CO in the ambient, and don't analyze flue gases.
I found some information about Carbon Monoxide on the Health Canada website - Here (http://www.hc-sc.gc.ca/ewh-semt/air/in/poll/combustion/carbon-eng.php)
QuoteHealth Canada's Residential Indoor Air Quality Guidelines
Health Canada has developed an indoor air quality guideline for carbon monoxide in residences. The guideline sets recommended maximum carbon monoxide levels for two types of exposure:
•The short-term limit of 25 parts per million (ppm) based on a one-hour average is meant to prevent the immediate health effects that may occur from exposure to CO for a short period of time (e.g. one hour).
•The long-term exposure limit of 10 parts per million (ppm) based on a 24-hour average protects against health effects that may be caused by repeated exposure to CO over a long period (e,g, over days or weeks).
Health Canada's recommended limits are set to protect people with pre-existing heart problems from extra stress on their heart or lungs due to CO exposure.
The most serious, noticeable symptoms of carbon monoxide poisoning will occur at levels much higher than Health Canada's guidelines.
Carbon monoxide levels in Canadian homes with properly functioning fuel-burning appliances are usually well below the limits recommended by Health Canada.
I found another government of Canada / CMHC article about Carbon Monoxide - Here (http://www.hvactechgroup.com/files/CO.pdf)
Quote(30 ppm) CO detectors are not allowed to sound alarm unless this concentration is maintained for more than 30 days.
We just had Patrick Bergeron from IPEX give a course on the new System 636 this morning. Very interesting. Lots of areas we now have to watch out for with the TSSA. Cut into a old ABS system to get into a A-coil and have to replace the whole flue vent with system 636. He just had a meeting with the TSSA yesterday over the code changes. Did not make the boss happy at all.
Just wait until you have to use that primer!!! What a mess.
I don't agree that you would have to replace the entire vent system with 636 just for cutting it to access the A-coil.
Quote16. I am a gas fitter – If I replace the venter motor assembly – Do I replace the whole venting system?
If the vent is in good condition – No. Simply replace the motor and attach it with type of vent that is currently used on that appliance. Replacing a part of the appliance does not necessitate the whole vent be replaced.
This is saying if you had to cut the ABS to remove the ventor motor, then you could simply replace the motor and not the venting. Not all ventors are installed with rubber couplings and clamps, some are actually glued into the ventor motor, therefore you would have to cut and replace a section of ABS. You would have to be diligent and ensure the rest of the venting is intact. If you cut the vent pipe to access the coil, then installed a coupling, who would know??? It's the same as having to cut the vent to replace the heat exchanger, the TSSA Questions & Answers clearly states
Quoteand attach it with type of vent that is currently used on that appliance
Quote19. Does the combustion air piping need to be certified to ULC S636?
No – the combustion air pipe is not exposed to flue gases and does not need to be certified.
So if your cutting the inlet vent pipe, there are no worries.
The above quotes were taken from the Questions & Answers Notice (http://hvactechgroup.com/files/ULCS636.pdf)
The actual code was amended and came into affect August 1st, 2007.
Quote8.9.5 Venting systems, or total vent run if less than 3 ft (900 mm), that employ plastic vents shall be installed such that the first 3 ft (900 mm) from the appliance outlet is readily accessible for visual inspection except for direct vent appliances such as fireplaces that are intended to have short vent lengths to be concealed for decorative purposes.
8.9.6(a) Until July 1, 2008, vents constructed using plastic piping shall be certified to ULC S636 except for special fittings (non standard vent sizes and components) which may include:
a. entire vent systems supplied with the appliance that are not comprised of standard vent sizes and components;
b. transitions with or without condensing lines; and
c. termination kits.
8.9.6(b) After July 1, 2008, vents constructed using plastic piping shall be certified to
ULC S636.
What TSSA is telling you comes from Director's Advisory FS101-07 (http://hvactechgroup.com/files/FS10107.pdf)
Key word here is ADVISORY; it's not even a Director's order. So they advise you to follow it, but it doesn't have to be followed until it becomes an ORDER.
The only thing you have to adhere to, at this point, are Clause 8.9.5 and 8.9.6 of the CAN/CSA-B149.1-05 Natural gas and propane installation code.
You can always apply for a Variance if Clause 8.9.5 or 8.9.6 cannot be met - Here (http://hvactechgroup.com/files/Variance.pdf)
*Update* December 12, 2012 - Download the updated TSSA Application for a Variance - Here (http://www.hvactechgroup.com/article.php/20121220083108330)
This is just my opinion, and TSSA is terrible at replying to emails regarding interpretation. I follow the gas code and Director's Orders, plain and simple. I would never force my customer to replace their venting because I cut it to access the coil. Unless my customer worked for the government or TSSA. :D :D
We got nailed today for using ABS after Aug 1st. One of the service techs had to go out and replace the venting pipe from start to finish. Here is what happen the furnace was installed prior to Aug 1st. There was no gas or gas meter installed yet. Union gas comes in after Aug. 1st and runs the gas line and meter. The inspector tags it for the use of ABS. So now the fun starts. Boss is telling us what ever you do don't touch the ABS lol ;D
Quote from Director's Advisory FS-102-07
(http://hvactechgroup.com/files/advisory/FS10207.pdf)
QuoteThere may be situations (homebuilder and condominium builders) where the vent is installed in advance of the appliance and its activation. Under the circumstance where the vent is installed before August 1, 2007 and the appliance is installed and activated after August 1, 2007, the date in which the appliance is activated is the determining compliance date.
They could have applied for a variance, but replacing the vent is cheaper.
I don't believe in problems, only opportunities, and this whole venting issue is a way for guys like us to make more money. Bring it on! ;)