You didn’t mention where you live, the size of your GSHP or details of the ground loops. However, average daily use of 43kW equals 15,695kW/yr - that’s excellent, especially with teens living at home! I wouldn’t be too worried about efficiency at that consumption rate.

This is what I would recommend. DON’T have an annual service contract, save your money. I would want to have installed, if you do not now have, a flow meter (see link below) and temperature gauges measuring ‘Entering Water Temperature’ (EWT), ‘Leaving Water Temperature’ (LWT) of the ground loops, as well as a place to stick a thermometer into the the return & supply plenums or main ducts to measure temperatures and determine temperature differentials (∆T). The ‘See-Through’ flow meter will not only allow you to accurately measure flow in GPM but also allow you to visually see if there is any air in the system or impurities as may be indicated by changes in fluid colour.

This way you will be able to record and ‘see’ any changes (∆T) that may occur. Keep your own logbook at the HP, record all measurements regularly, including filter changes. You can even note temperature changes before and after filter swap outs (at plenums or main ducts). Examine used filters by holding them up to the light and comparing them to new unused filters.

I have never had an annual service contract for our geothermal installation (11-years old, 12th-heating season) and it has never broken down or needed a service call. I’ve changed the filters myself, vacuumed the coil occasionally, changed the fan belt and checked that the condensate drip tray and drainage pipe were clean and clear. So far with the money saved on annual service contracts we can heat our home for 3-years!

IMO

SR

Here is a link that might be useful: Blue-White Flow Meter

We were required to have them service annually for the first 3 years to get warranty, after that we pushed it a few months (to Nov instead of Aug), then skipped a year. So no, I won't go contract with anyone. But what do you think about getting a 2nd opinion so to speak? Though I probably should have installer do the metering you suggested so there is no finger-pointing.

I know the 80-gal wired HHW (and 7 loads of laundry on average per week, plus showers esp. during XC/track season, plus 1 or sometimes 2 loads in the DW each day) do add up (esp. since we're on a well) - and then the electric dryer too (though I try to do loads back-to back starting with Hot Cottons and ending with Delicates to use residual heat).

Ironically, when I just looked at the actual usage the past 7 years, we've been using less (or the same) since DS started running (in fall of 2010) than we did the first few years that he was in grammar school so I can't blame it on showers and laundry! We have gotten the lockout set so we don't see the 2500-kWh winter months anymore, but we don't go below 985 or so either (in the early years we had some about 965 but I think I've gotten used to AC in the summer LOL!).

We're on a budget plan so we pay $236/mo (I thought about 18cents/kWh but it turned out to be more like 16) every month(so I figured 15,773 kWh but it's been more - see below) and don't have to take out a loan each winter LOL. It could be going up soon though when our 7.79 cent/kWh generation rate expires. Unit is 4 ton Tranquility 27 with DSH, a pair of 279-foot wells. My zone *used* to show in posts, we're in the foothills of the Berkshires, NW CT.

Actual usage (varies from just under 1000 to over 2000 kWh depending on month), averaging more like 49 kWh/day this past year (but we've had a couple of really cold winters in a row, though looking at usage there was only 1 low year - I think we were without power for about a week late Oct/early Nov 2011, the winter of 2010-11 may have been hard too):

11/13 -10/14 18032
11/12 - 10/13 17338
11/11 - 10/12 16010
11/10 - 10/11 18785
11/09 - 10/10 17179
11/08 - 10/09 18111
11/07 - 10/08 18822 (really big bill in Dec 07, I think we were still messing with settings, and had too large a setback overnight)

Is 49 kWh/day still good for family of 4 with electric dryer, electric HWH, and a well? We keep thermostat set at 67 during the winter and 74 in summer (though I have been known to bump it down to 72 when I'm having a hot flash). Only set back 2 degrees at night (downstairs) or during day (upstairs, I stay downstairs) and then come up 1 degree at a time (we were told not to program the T-stat but to me it seems silly to heat/cool unoccupied spaces, though we found more than 2 degrees at a time was causing heat strips to kick in). We also started turning the breakers to the heat strips off most of the year and only turning them on Thanksgiving - Easter, spring of 2009 I think after our first full year of bills.

This post was edited by ajsmama on Thu, Nov 13, 14 at 10:23

We have a Tranquility 27 3 ton from the same year, and the only maintenance needed to date has been filter replacement and duct cleaning. I initially did an acid rinse every year (to prevent hard water build up) but have since been told we do not need to. I suppose I should think about a belt in the next few years.

System works pretty well. We have an open loop/well set-up. Just got the de-superheater (hot water generator) hooked up and we expect that to be good. We'll see. The only reason we have the heat strips at all is as back-up in case the well pump fails, and we only enable the heat strips if we're going to be away from the house during bad weather for some days. Don't want to come home to frozen pipes!

The heat pump has gotten us through some pretty bad stretches of extended wind and cold, and we live in a 100 year old house with marginal insulation and some leaks, which we gradually tackle.

With the collapse in natural gas prices the savings I anticipated isn't so great as I'd hoped, but I'm still glad we did it. We're comfortable with slightly lower temperatures than we were with the old gas furnace and its blasts from cold to hot. And there's a few weeks most every summer when we're glad to have the air conditioning!

Good luck,

Mark

ajsmama,

How large is your house? I am curious to know the size.

Are you comfortable keeping the temperature at 67 in the winter or do you set it this low to save energy costs?

Have you tried calculating the annual heating and cooling costs? Here is the method I use:

1. Find the average usage of electricity for the months that you know you used neither heating or cooling. This is will be your average usage for all electrical appliances other than HVAC.

2. Find the average of the months you know you used heating. Subtract the average you used in step 1 and multiply by the number of heating months. This is approximately your heating costs.

3. Repeat step 2 for the cooling months. This will be approximately your cooling costs.

4. Repeat steps 1-3 for at least two years of data. This will help average out hot summers and cold winters.

The calculations assume that the electricity used outside of heating and cooling is about the same for each month. It is not a precise method but it gives you an idea of how much your spending on HVAC.

See my new thread about leaky coils. This has probably been a slow leak over the past few years, according to the installer. Not sure if this is covered under the 10-yr limited warranty but I don't think labor is covered and he said it's about a 4 hour job!