Dear Ken: We had a furnace installed and you can hear the blower all over the house. Is this normal? — Jill

Answer: New furnaces are noisier. That’s because there’s an extra motor to kick out fumes plus thinner metal is required for greater energy efficiency. Make sure there is a rubber isolation collar somewhere above the furnace that connects to the main ducting system. Look for a band of leathery, black plastic fabric built into the sheet metal. Not all heating systems have one. If yours doesn’t, ask the furnace company about it.

Finally, turn off the electricity and and feel around its insides, or if your cellphone is one of the smaller models, you can use its camera to inspect the interior of the blower’s motor; even the tiniest foreign object can create a noisy, out-of-balance condition.

Dear Ken: We notice frost on the interior walls, ceilings and inside the attic when it’s really cold outside. What can we do? — Marti

Answer: The inside of your house could be too moist. Cold air holds less moisture, so turn down humidifiers when outside temperatures dip below 25 degrees.

Also, check your attic insulation; you need at least 14 inches of blown material. It’s also important to ensure the insulation covers all the ceiling area, to the edges of the living space — but not too far, as it can interfere with the soffit vents.

Builders in the coldest parts of the country, such as the Great Lakes states, pay a lot of attention to attic ventilation. That’s because it’s vital not to trap warm (and moist) air inside the attic spaces, which can lead to ice dams along the roof edges.

In your case, you’re trapping moisture — hence, the frost — that needs to be carried away by the vents. So make sure there is some cross ventilation — either side to side or bottom to top.

Finally, make sure your bath fans vent directly outside, not into the attic space. Warm, moist air from these fans can cause not only frost but mold buildup and insulation deterioration.

Dear Ken: We recolored our old bathtub about four years ago with a kit we found at the paint store. Now, the old color is starting to show through again. What can we do? — Ann

Answer: You need professional help. There are basically two processes you can consider. The first — and cheapest — is to apply an acrylic resin or epoxy sprayed-on coating. Start by etching the finish with a strong chemical, then apply any color you want to match the décor. This will cost several hundred dollars and usually comes with a five-year warranty

For three or four times that amount, a tub lining company can insert a precisely molded acrylic insert over the old tub. These last much longer as many come with at least a 25-year warranty. So it’s up to you and your budgetary constraints.

Dear Ken: A technician says that a dryer vent pipe longer than 8 feet will cause troubles with the motor. Do you agree? — Johnny

Answer: No. At my house, the vent is smooth, galvanized pipe about 20 feet long with two 90-degree bends, and it does fine. Admittedly, it might be taking longer to dry my sheets than it would with a shorter run, but that’s the way it goes. The rules for dryer vent length changed several years ago so builders have been forced to relocate laundry rooms to an outside wall, or run the duct vertically through the roof to meet the new demands. But for those of us with older houses, we have to live with the old, less stringent installations.

Make sure you clean out your dryer vent a couple of times a year. Lint tends to accumulate at each end — behind the dryer itself and at the exterior vent cap. As you would expect, longer runs tend to need more attention than direct-to-the-outside setups. If you have one of those vertical pipes, you should check the first few feet of vent two or three times a year, as the lint tends to accumulate in the pipe and then fall to the bottom.

One other impediment to efficient drying are dryer sheets. Their chemicals can build up an invisible residue on the lint screen. Here’s a test: Run water on it. If the water just sits there and doesn’t run through, you are attenuating the air flow and so increasing drying time. Scrub the screen with warm soapy water and you’re back in business; check it at least once a month.

Dear Ken: A friend told me to use some enzyme-type chemical added to my septic tank to help the bacteria in the tank. Is that a good idea? — Peter

Answer: Probably not. Normal household use is all you need to encourage and maintain the helpful flora in the tank that digests the waste. If you add more bacteria, you can start over-processing sewage. That means the stuff doesn’t hang around long enough to settle as sludge, and therefore particulates can migrate into the leach field. Enough of them can plug it up, and then you’ve got an expensive mess on your hands.

Bottom line: Baby your system by using biodegradable laundry products, and avoid strong chemicals such as paint, solvents and oil or grease. Use it normally without additives, and it will serve you well.

Ken Moon is a home inspector in the Pikes Peak region. His radio show airs at 4 p.m. Saturdays on KRDO, FM 105.5 and AM 1240. Visit aroundthehouse.com

Dear Ken: We had a furnace installed and you can hear the blower all over the house. Is this normal? — Jill

Answer: New furnaces are noisier. That’s because there’s an extra motor to kick out fumes plus thinner metal is required for greater energy efficiency. Make sure there is a rubber isolation collar somewhere above the furnace that connects to the main ducting system. Look for a band of leathery, black plastic fabric built into the sheet metal. Not all heating systems have one. If yours doesn’t, ask the furnace company about it.

Finally, turn off the electricity and feel around its insides, or if your cellphone is one of the smaller models, you can use its camera to inspect the interior of the blower’s motor; even the tiniest foreign object can create a noisy, out-of-balance condition.

Dear Ken: We notice frost on the interior walls, ceilings and inside the attic when it’s really cold outside. What can we do? — Marti

Answer: The inside of your house could be too moist. Cold air holds less moisture, so turn down humidifiers when outside temperatures dip below 25 degrees.

Also, check your attic insulation; you need at least 14 inches of blown material. It’s also important to ensure the insulation covers all the ceiling area, to the edges of the living space — but not too far, as it can interfere with the soffit vents.

Builders in the coldest parts of the country, such as the Great Lakes states, pay a lot of attention to attic ventilation. That’s because it’s vital not to trap warm (and moist) air inside the attic spaces, which can lead to ice dams along the roof edges.

In your case, you’re trapping moisture — hence, the frost — that needs to be carried away by the vents. So make sure there is some cross ventilation — either side to side or bottom to top.

Finally, make sure your bath fans vent directly outside, not into the attic space. Warm, moist air from these fans can cause not only frost but mold buildup and insulation deterioration.

Dear Ken: We recolored our old bathtub about four years ago with a kit we found at the paint store. Now, the old color is starting to show through again. What can we do? — Ann

Answer: You need professional help. There are basically two processes you can consider. The first — and cheapest — is to apply an acrylic resin or epoxy sprayed-on coating. Start by etching the finish with a strong chemical, then apply any color you want to match the décor. This will cost several hundred dollars and usually comes with a five-year warranty

For three or four times that amount, a tub lining company can insert a precisely molded acrylic insert over the old tub. These last much longer as many come with at least a 25-year warranty. So it’s up to you and your budgetary constraints.

Dear Ken: A technician says that a dryer vent pipe longer than 8 feet will cause troubles with the motor. Do you agree? — Johnny

Answer: No. At my house, the vent is smooth, galvanized pipe about 20 feet long with two 90-degree bends, and it does fine. Admittedly, it might be taking longer to dry my sheets than it would with a shorter run, but that’s the way it goes. The rules for dryer vent length changed several years ago so builders have been forced to relocate laundry rooms to an outside wall, or run the duct vertically through the roof to meet the new demands. But for those of us with older houses, we have to live with the old, less stringent installations.

Make sure you clean out your dryer vent a couple of times a year. Lint tends to accumulate at each end — behind the dryer itself and at the exterior vent cap. As you would expect, longer runs tend to need more attention than direct-to-the-outside setups. If you have one of those vertical pipes, you should check the first few feet of vent two or three times a year, as the lint tends to accumulate in the pipe and then fall to the bottom.

One other impediment to efficient drying are dryer sheets. Their chemicals can build up an invisible residue on the lint screen. Here’s a test: Run water on it. If the water just sits there and doesn’t run through, you are attenuating the air flow and so increasing drying time. Scrub the screen with warm soapy water and you’re back in business; check it at least once a month.

Dear Ken: A friend told me to use some enzyme-type chemical added to my septic tank to help the bacteria in the tank. Is that a good idea? — Peter

Answer: Probably not. Normal household use is all you need to encourage and maintain the helpful flora in the tank that digests the waste. If you add more bacteria, you can start over-processing sewage. That means the stuff doesn’t hang around long enough to settle as sludge, and therefore particulates can migrate into the leach field. Enough of them can plug it up, and then you’ve got an expensive mess on your hands.

Bottom line: Baby your system by using biodegradable laundry products, and avoid strong chemicals such as paint, solvents and oil or grease. Use it normally without additives, and it will serve you well.