We cant stand the pinging ducts when the furnace goes on

Each year, thousands of Arizona residents email or call Rosie Romeros radio show with questions about everything from preventing chimney fires to getting rid of tree roots in their sewer systems. His goal is to provide answers that suit the specific lifestyle wherever someone lives in Arizona. Here are questions about home maintenance and improvement from the Tucson area.

QUESTION: I just moved into a townhouse that was built in 1977 and still has the original equipment inside for heating and air conditioning. When we moved in, we had the ducts cleaned out to get rid of the dust and debris. The cleaning company actually found a beer can and beer bottle in one duct. So now that the dust has been vacuumed out, theres still a pinging sound in the ductwork whenever the heater kicks on. It sounds like water banging on a tin roof. It doesnt bother me, but it really upsets my wife. What should we do about it?

ANSWER: It does sound as if you have the original HVAC equipment in your home. The noise is due to thermal expansion and contraction. In current installations, the furnace installer puts in an expansion collar in between the equipment and any rigid ductwork to prevent that noise from happening.

You might want to call a qualified HVAC firm and have them take a look at your ductwork to determine the necessary repair process. You might even want to get an estimate of how much it will cost to replace your HVAC system.

Q: I recently took the face plate off my thermostat and noticed when I looked at the wiring inside that one yellow wire had been cut and was not connected to anything. What does that mean? Everything seems to be operating normally.

A: If your thermostat works properly and your heating comes on and off at the right times, that loose wire probably doesnt mean anything. Generally, there are many small wires inside one big wire, and sometimes the installer doesnt need all of them to connect the thermostat. However, if youre really worried about the situation or youre having trouble with your heating and cooling systems, you should have a qualified HVAC repair person take a look at everything.

Q: I missed putting pre-emergent weed killer down on the gravel beds in my yard a few weeks ago. Now I already have some weeds growing. Is it too late to apply pre-emergent now?

A: Pre-emergent can be applied at any time, but it may not work very well. Its best to apply it just before a rainy period to keep seeds from germinating. If weeds have already started sprouting, you need to use herbicides to get rid of them or you need to weed by hand. Be very careful about using chemical products to ensure that you dont damage your other plants. Remember, pre-emergent will also kill any spring wildflowers that may sprout in your yard.

Q: I have grubs everywhere among my plants. How do I kill the grubs without harming the earthworms that are plentiful in my garden?

A: There are several brands of grub killers at nurseries. However, all of them will harm the earthworms. Youre very lucky to have earthworms, so you may have a very hard choice to make. You can try getting rid of the grubs one by one. Pick them off your plants and throw them out in the street, for example.

Originally posted here:
We cant stand the pinging ducts when the furnace goes on