HVAC System 20 Years Old, Time to Proactively Replace??

[3930dave]

It's been a problem with rentals... the old Mercury Stats would last a lifetime and very reliable for Millivolt systems too!

I've gone from never having Stat problems to having them... tenants have on wrong setting, remove batteries, etc...

With the Heat Pump units they freak when the temps drop below freezing and Auxiliary or Emergency Heat is indicated... always get calls saying the system needs to be checked when the January Electric bills hit.

Aside from the tech/reliability issues, you also have the same key issue I now have to deal with - sky high electricity rates, that show no sign of slowing down, or should I say Up.....

That trajectory has removed all-electric from my future plans, at least when on-grid.

I do like ground or water-sourced geothermal as a technology just fine though - my issue is where I live, legislation wise....

Rgds, D.

 

[crackerjack222]

"Interesting with new systems you can not turn the thermostat below 60, I normally set it for 55 when we are away Feb-March. Any idea why they set the limit so high?"

The builder at our vacation home installed a thermostat that would not go below 55*. I replaced it with one that will go to 41*. Dont remember the make, but I got it at Home Depot. In 13 years, the only problem came when the power was off for an extended time and the temperature was near zero. I always turn the water off and open a couple of valves when we leave but this time both commodes, tanks and bowls were shattered after the water in them froze. A few soft drink cans in the pantry split open. The pipes are pex which can freeze with out harm. Now when I leave, I also flush the commodes and put a cup or so of RV antifreeze in the tank and bowl.
At our home in S. TX I had a top-dollar Trane variable speed system installed 3 years ago. It replaced a water source heat pump that I installed when the house was built in 1993. The problem with the water source system was the mineral buildup from pumping lake water thru it. I would have to replace the water pump check valve about every 4 years and run acid de-scaler thru the system about every three years. The new Trane system is significantly more efficient than the old system. We are all electric and my maximum bill, winter or summer is about $175, where with the old system it would be about $275.

 

[ultrarunner]

When I winterize the cabin I drain as much water as possible and then add RV antifreeze to the toiler bowl, tank, traps, etc... knock on wood it has been effective.

We use to have heat on at 45 but one winter a bear did a number on the propane tank... lost $900 of propane too...

 

[kenmac]

if you are considering a VRF system, get ready to come off some bucks. They ain't cheap. about 20 k to install a 2.5 -3 ton VRF system. You talk about electronics . the VRF units are loaded

 

[dadster4]

I wouldn't spend the money until some major fix is necessary, you could easily get another 10 years out of the present system. Pull off an end cap and check the inside of the ducts to see how dirty they are, I've seen 12 x 8 duct reduced to a 4" round hole in old homes. Most systems supply ducts are sized properly, but the return is very often undersized, insulating duct wrap would definitely be a benefit. A humidifier is a good idea, but electronic air cleaners can be good or bad...they need to be cleaned often to be efficient, I like the pleated 4" thick filters the best. It may be possible to zone the attic bedroom if another supply can be run directly from the furnace plenum.

 

[CADplans]

if you are considering a VRF system, get ready to come off some bucks. They ain't cheap. about 20 k to install a 2.5 -3 ton VRF system. You talk about electronics . the VRF units are loaded

I helped design what we believed was the original VRF drive (mid 1980's GE),,,
the cost should be down to $100 per unit by now,,, :confused2:

Oh, well,, somebody has to get rich,,I guess. :thumbsup:

Not me,,, :laughing:

 

[kenmac]

I wouldn't spend the money until some major fix is necessary, you could easily get another 10 years out of the present system. Pull off an end cap and check the inside of the ducts to see how dirty they are, I've seen 12 x 8 duct reduced to a 4" round hole in old homes. Most systems supply ducts are sized properly, but the return is very often undersized, insulating duct wrap would definitely be a benefit. A humidifier is a good idea, but electronic air cleaners can be good or bad...they need to be cleaned often to be efficient, I like the pleated 4" thick filters the best. It may be possible to zone the attic bedroom if another supply can be run directly from the furnace plenum.

yep, I can't understand why guys always under size the returns. Never understood that. It presents a problem when people install a super duper catch everything air filter they bought from the box store ,thinking they are doing something good, when actually they are doing more harm with the super duper filter than with the cheap filters.

If he can get a 98% gas furnace with a hp or regular a/c for a descent price, I'd go for it. You will have 2 stage gv, and a dc direct drive variable speed motor. Or you could really splurge and get VFR mini split to run the entire house . the hp will heat down to about in the low teens or 0. HVAC systems are evolving every day.

 

[MossRoad]

Thanks all for the input very much appreciated.

I keep thinking since I am away 2 months during winter, I would hate for the heat exchanger to go and I am 2500 miles away and trying to get it fixed/replaced from a distance. I replaced my 10 year old no problem water heater with the same idea.

Our gas forced air furnace is somewhere over 30 years old. It was in it when we bought the house. The original owner left us his spare belt "In case the belt on the blower goes out." Its still hanging on the nail in the post next to the furnace. :laughing: We have it inspected every other year or so. As others have mentioned, get some remote temperature monitoring equipment installed so you can check on the house while you are away. Also, make sure and leave a key with a trusted neighbor to let a repair person in should it come to that.

As for your water heater.... that's a different concern. If the furnace quits, you have a day or two to get heat into the house before the pipes freeze. If you shut off the water in your house and drain everything and pour some RV antifreeze into each toilet and sink trap, you have several days or even longer, depending out where your water line enters the house. If your water heater quits working, you just have cold water.... but if your water heater bursts and you aren't home, there's a flood. So that one's a different problem and depends on how well your take care of your water heater. Again, if you shut off the water in your house while you're away and shut off the water heater and drain things down, its not a concern while you're gone.

 

[kenmac]

Our gas forced air furnace is somewhere over 30 years old. It was in it when we bought the house. The original owner left us his spare belt "In case the belt on the blower goes out." Its still hanging on the nail in the post next to the furnace. :laughing: We have it inspected every other year or so. As others have mentioned, get some remote temperature monitoring equipment installed so you can check on the house while you are away. Also, make sure and leave a key with a trusted neighbor to let a repair person in should it come to that.

As for your water heater.... that's a different concern. If the furnace quits, you have a day or two to get heat into the house before the pipes freeze. If you shut off the water in your house and drain everything and pour some RV antifreeze into each toilet and sink trap, you have several days or even longer, depending out where your water line enters the house. If your water heater quits working, you just have cold water.... but if your water heater bursts and you aren't home, there's a flood. So that one's a different problem and depends on how well your take care of your water heater. Again, if you shut off the water in your house while you're away and shut off the water heater and drain things down, its not a concern while you're gone.

hard to believe that furance is 30 yrs old and doesn't have a cracked heat exchanger. That metal has expanded and contracted alot over 30 yrs.

Trane with tube heat exchangers were bad about splitting at the tube seams. I hated the old rust bucket carrier / bryant furnaces too

 

[MossRoad]

hard to believe that furance is 30 yrs old and doesn't have a cracked heat exchanger. That metal has expanded and contracted alot over 30 yrs.

Trane with tube heat exchangers were bad about splitting at the tube seams. I hated the old rust bucket carrier / bryant furnaces too

I agree. For the past 6-7 years we've been heating with wood for 80% of our needs, so it doesn't get quite the workout it used to I'm sure. The thing now mostly gets used for the air conditioning, which is also older than 21 years (as long as we've been in the house). We have them check the air conditioning system and the heat exchanger every couple years. And we have good working carbon dioxide sensors in the house as well. I'm on my third water heater, though! First one started leaking about 5-6 years after we bought the house. 2nd one thermocouple went bad after about 5 years. When I went to remove it, I had a hard time getting the two bolts out that hold the whole burner assembly in. After stripping them out, came to find out they were left hand thread. What's that about? Turns out the store chain that was selling them was selling mobile home water heaters for residential use and there was a legal settlement that if you reported it, they'd have to send you a new burner assembly for residential house use free of charge with adapters to make it right hand thread. Well, that was great, I got my new burner assembly for free, but the mounting holes in the water heater themselves are what strips out, not the screws. So I had to use larger self tappers to mount it. Worked out well for about 5 more years, and when the thermocouple went out again, I replaced the entire unit. Been about 3 years now. So far, so good.