Leaks from vents during rain? Call an HVAC company

Q: After some recent heavy rains, I developed a leak in my Mexican tile roof that is only 2 years old. A lot of water leaked out of a cold air vent. I actually collected an inch of that water coming out of the duct in two hours’ time. Should I call a roofer to get this fixed?

A: You can call a roofer to check out the problem, but it seems possible that if you have that much water dripping out of a supply air register, it could actually be a condensation problem with the ducts themselves. In stormy weather, these situations may stem from drastic but temporary changes in the relative humidity and dew point. On the other hand, leaks out of a ceiling return register are usually due to a roof leak. My guess is that your problem is with the supply register closest to the air-conditioning unit where the ducts are the coldest and the condensation the most severe.

You may need some changes in your heating and air-conditioning system to prevent these leaks from happening in the future. It might also be the result of problems with your air conditioner’s condensate drain line. So call a qualified HVAC repair company for help.

Q: Are coffee grounds good to spread around my trees and plants here in Arizona? Will they help the plants grow faster?

A: Coffee grounds are good for all kinds of plants that are grown here because they contain protein, nitrogen and acids that plants need. As you know, our soil in Central and Southern Arizona is extremely alkaline. So adding the acidic coffee grounds can greatly improve the growth of your plants. If you have a compost pile, you want to regularly add the grounds to the mixture of leaves and vegetable matter.

Q: I recently pruned back my Chinese elm tree quite a bit to try to get it to form a canopy, and now the tree isn’t doing very well. It isn’t growing very quickly, and it seems to have foliage problems. What can I do to help it?

A: It sounds as if you cut it back excessively. That’s not a good thing to do with a smooth-barked tree like a Chinese elm. It makes the tree very susceptible to sunburn. A rough-barked tree like a mesquite can take a little more sun, but not a smooth-barked tree. You need to get some burlap from a nursery to wrap around the trunk for a while until the canopy grows more foliage to shade the bark. Wrapping it that way is better than trying to paint the trunk. Once it improves, you can remove the burlap.

Q: My house was built in 1971, and I recently found out that the electric wiring that is connected to my oven is made of aluminum rather than being made of copper as was used in the rest of the house. Is that dangerous, and do I need to replace the wiring?

A: The truth is that builders did that kind of thing years ago to save money when houses were constructed. But eventually, they found that sometimes aluminum wiring can vibrate and end up loosening the screws attaching the wires to appliances. Those loosened screws create a gap that can result in arcing. But fortunately, the aluminum wires in ovens were connected with heavy lug nuts that really clamped down on the wires, creating far less in the way of risk. Probably, your oven should continue to operate safely with its current wiring. But just in case, you may want to contact a qualified electrician to inspect the aluminum wiring connections to the circuit breakers to make sure they are all good, tight connections.