I had breakfast with someone this morning that was telling me that he has a friend that's a HVAC repairman and that he claims these pumps are in need of repair within 5 years.  I've also heard over and over that solar hot water systems don't work either and my system is proof that it works very well when designed properly and you know what to expect.  I think the key phrase here is "what to expect".  I expect to spend around $ 5-6K for a heat pump ( real rough guess, 4ton) and think the thing should run well for 15-20 years without any complete melt downs, is this about right? What maintance is to be expected? When these things have problems should you replace componets like the motor, coil etc. or replace the whole thing, say at 10 yrs?

General life expectancy on a heat pump is 25 years.

There is a post on this forum about a unit that is still running after 38 years.

Dewayne, what type of things have you seen crop up with the pumps if anything at all?

I had to have the blower and blower motor replaced on my system to the tune of $600. The repair guy said it looked like someone welded the moter shaft to the blower sometime in the past. The drain pan on the unit looked like it was beginning to rust, I had the former owner repair it before I brought the house. It looks like they used some kind of tar to seal over the pan, but it looks waterproof to me.  I had the shutoff valve replaced, that cost $120 to do, it was shutting off too quickly, causing the pipes to vibrate and banging against the joists in the basement, the new value solved the problem. Other than that I'm not aware of any problems with the 19 year old open loop system I have.

As far as pumps go, my parents have well water (but not geo-themal heating) and there pump is 30 years old and they never had a problem with it.

Thanks guys. I'm just trying to cover all my bases so I know what to expect. You can't run a car for 4 years without dumping money into it so I'm not scared of $500 here or there. I'm certainly going to try doing all the service/repair work myself. I'm pretty good at understanding systems, it just takes me awhile figure them out if I haven't messed with them before.

I have been doing this for three years and have not had to do any service on heat pumps that we have installed. I hear accounts of loop pumps needing to be replaced in 5 - 10 years. They would be within your $500 here or there budget. Other than that the fan motor and heat pump compressor are the only other moving parts.

Just a clarification...

25-30 years can be expected on a geothermal heat pump, not an air source heat pump. 10-15 years is what's expected on air source heat pumps.

We've done water source heat pumps starting almost 14 years ago. All but one of them are closed loop systems. Every closed loop system we've had eventually needs to be re-pressured/re-purged. It's a maintenance headache. That's the number 1 maintenance issue we've seen. That's the biggest reason we started looking into EarthLinked DX geothermal. Now we only do DX.

That's not to say that all systems will definitely have to be re-purged/re-pressured. It's just been our experience that it has to be done. Of course there are boiler fill valves, glycol feeders, etc...but why not stick with something simpler, more efficient, and more cost effective to install?

Is the Earthlink DX something you can install yourself ? The advantage of a horizontal loop setup is a smuck like me can dig trenchs on weekends and drop pipe into them and not spend $25K on a system.

No, you can't install it yourself. Yes you can dig your own trenches for it to save on the install.

The "it" you're referring to is the horizontal system, correct? Am I correct in a 3-4 ton Earthlink DX being around 25K? Thanks.

The "it" is the heat pump and loop system. If you have some refrigeration ability (brazing/leak testing) then you could possibly go to a training and get certified to install the lines yourself.

As far as installed cost, it varies tremendously based on where you are. In my area, the installed cost on a new home, including duct work, ground loop installed, excavation, drilling, controls--basically turn key installation--ranges from about $18,000-$24,000 for a drilled or excavated 3-4 ton EarthLinked system. Different contractors have different overhead, labor, and profit numbers than others. Some are just more efficient than others, and it's up to them on how much they need to make on an install.