Here Comes The Cold
A preseason heating system checkup can prevent big problems - and big expenses - this winter.
June 18, 2008
September's here, and heating season is just around the corner. It's the perfect time to get out and make sure your heating system is ready for the next few months. A bit of routine maintenance will ensure your plants will have the warmth they need, when they need it.
The National Greenhouse Manufacturers Association offers heating guidelines (you can download a copy at www.ngma.com/downloads.htm), including a 12-point preseason maintenance checklist. We spoke with a few experts in the field - Russell Zabel, general manager, Delta T Solutions; Gregory Gawne, vice president business development, Total Energy Group; and Chris Smith, marketing manager, L.B. White Co. - to get their input on some of the items on the NGMA list, as well as a few other helpful tips on how to get the most out of your fall heating maintenance:
1. Check equipment for physical damage. Check the sheet metal, fans and air movers, wiring, fuel piping and vent system. "You're looking to make sure nothing is broken or dented," says Gawne.
"Make sure warning and data labels are clean enough and in legible condition," Smith adds.
This is also a good time to check gas pressures and gas pipe connections, suggests Smith. "Have a trained gas professional use a gas gauge to ensure pressures to the house and heaters meet pressure requirements stated on the data plate and in the owner's manual," he says.
You should also spray leak detection liquid on all places gas pipes or hoses are connected. "Soapy water works as an alternative," Smith says. "The connections will bubble if there is a leak."
2. Check for the cleanliness of the equipment's heat exchanger and burner. "Anything that's gas-fired, you need to go through and vacuum out the heat exchangers and verify the unit fires properly and cleanly, says Zabel.
That's particularly true if the unit has a power burner, he adds. "Make sure you tune up the CO2 on anything that has either a fan-assisted or power blower on the burner. That's something that almost nobody does that they really should on an annual basis." Some of the new high-efficiency equipment has more bells and whistles that need some extra attention, Zabel says. "It doesn't take a lot of time, but it does take somebody who's qualified to do it and to do it with the proper tools."
3. Check the vent system. "Make sure your stacks are clean," says Gawne. "Make sure nothing has made a large nest inside over the summer."
4. Check to make sure no obstructions block the air intake or air discharge of the equipment. All heaters require space around them for safety, says Smith. "Make sure items were not set on top of the heater when it was not in use. Improper clearances could result in an accident."
5. Check lubrication of the motors on fans and pumps. With the power off, check to see that the motor shafts turn freely. "Don't wait until it's November when it's getting really cold and then all of a sudden you find out your pump doesn't work. This needs to be done prior to the heating season," Zabel says. "Work the pumps, and make sure there are no leaks or noises that would warrant some kind of service."
6. Check the belt tension on equipment that utilizes a centrifugal blower system.
7. Check the heat exchanger of the equipment for any signs of cracks or corrosion. A flashlight can be useful to check the inside and outside of the heat exchanger. "If you find rust or holes in the heat exchanger, you may need to replace the unit," adds Smith.
8. Check the heat exchanger of the equipment for signs of overheating. Metal that has been overheated will have a dark discoloring of the area that was overheated. Overheating could be the result of over-firing, improper venting or inadequate combustion air.
9. Inspect the burner for general cleanliness. It is not uncommon to find that spiders or mice have nested in the control or burner area.
10. Check the control wiring to make sure the connections are tight. "Visually inspect all places connections are made," White says. "For suspect connections, make sure the power is off and physically make sure they are made."
11. Check to make sure the manual valves are opened. In fact, says Zabel, it's important to take a good look at all of your valves, and if you find any problems, address them now.
"A lot of times when somebody finds a zone valve that doesn't work, they'll just open it up and leave it there with the intention of fixing it later." The result, Zabel says, is an area that's too hot. "But then you want it colder, so you turn it off and now it's too cold. You don't have any control over it. It's a waste of energy. The more your system performs the way it was designed, the more energy efficient it's going to be. Ultimately that's why you're doing a lot of this. Today, with energy, you don't want to be throwing 5 or 10 percent of your efficiency down the drain. That will cost you quite a bit.
12. If your greenhouse has an alarm system, make sure it is operational. Testing now can prevent those 3 a.m. false alarms, or more importantly, make sure you do get a signal when there really is a problem.
Maintenance Is Money
Walking your heating system through this list should ensure you don't run into any avoidable problems when you can least afford it. But the fear of losing heat in the dead of winter might not even be the best reason for a good preseason checkup.
"With the cost of fuel these days, the most important thing is efficiency," Zabel says. "Maintain your heating systems so they run efficiently. Have your pumps pumping properly. Make sure your water is treated so you don't have a bunch of rust running through the system, which is going to make it a lot less efficient.
Your heating equipment is an investment, Zabel says. "Treat it so it's going to have a long life and it's going to be efficient for a long time. If you just let it go and you don't clean it out on an annual basis and don't make sure everything's working properly, ultimately you're going to pay a lot more for fuel because you haven't maintained the equipment."