I think it is possible to go overboard, or be lured overboard, by the grooviness of a ''digital'' oven temperature setting. When you set the digital oven control to ''325F'', most ovens don't actually hold 325F, they turn on and off and the temperature swings around. ''On'' at something like 300F and ''off'' at something like 350F. That assumes the oven is perfectly calibrated which often isn't the case. With that much error and fluctuation, the apparent precision of setting the digital control to ''325F'' versus the apparent imprecision of turning a knob to ''325F'' is - well, it is an illusion. If precise oven temperature really matters, you'd want to use an oven thermometer placed in the same spot as the food. But does it matter? Does the food really care if the temperature is swinging around in a range of 300F to 350F, or would a range of 285F to 335F, or a range of 315F to 365F, work just as well? I really doubt it matters. You're not going to cook anything to an internal temp much over 200F anyway, so the oven temp just determines how much time it takes to get to the desired internal temp, and how browned the exterior gets by then. But those are very much influenced by the food (size? thickness? moisture?) and the cooking method (covered pot? foil? rack?). Bottom-line, the fancy digital temperature controls may sell ranges but I don't think they help cook food. I'd personally not care about that feature. The timer feature would be more important to me, not so much for cooking food but to ensure that I don't accidentally leave the oven on all night.

your best bet in this situation is to hire someone yourself to check out the system and give you an honest answer. If you check craigslist, you'll find guys offering to do "check ups" for $50-100 - just make it clear that you want a full inspection with line pressures, subcool/superheat delta-T and static pressure readings documented in writing on the repair order. Tell them before they come out that you aren't interested in a new system, just in getting the unit back to factory specs. Something is definitely wrong, and it's likely an inexpensive fix if you can get someone to actually break out their tools and check the system properly. Don't let them talk you into a new system, and don't believe the warranty company's lapdog. Google the warranty company's name to see what you're dealing with, most have terrible reviews.

Hello Your heat pump air-to-air sounds like the best options. If you dont need to use it for water the COP is quite high, usually COP-3-4. The COP means a ratio of what you get out vs what you put in. The COP of 3 is 3 times the heaat of what you put in. There are a number, some that get a COP of around 5 using source of 30F. Others list between 3-4 quite generally. Carrier is a maker of one type which has a COP of 3 and is a small size. When the source (outdoor temp) is low the COP goes down as does the output. (Below freezing especially). Its worth having an oil or wood or gas heater to go with the system as back up. Heat pumps that can heat water have to work harder as the water is warmer than the air used in buildings, so they use expensive CO2 heat pumps which will set you back about $5K easily. Therefore I would suggest keeping a boiler system, outdoor boiler. An indoor stove needs fresh air which is not ideal for heat pump system which works ideally with heat recovery on the ventilation system (extract heat from waste air at 90% or so efficiency). A neat approach may be to operate an air -to-air heat pump, aim for as high a COP as possible, but install a gas boiler if you have this. The smaller boilers, condensing systems, are surprisingly cheap. If you install a waste water heat recovery system which is just aa heat exchanger on you waste water from your shower, you can half the energy you need and thereby get by with a smaller boiler and consume only about 4-5kWh/day for shower water. A condensing boiler works most efficiently when working with water heating rather than central heating, and plus, the typical condensing system now heats so quickly that you dont need a hot water tank, reducing loses. You would still have at least 15KW available for heating the home. This can be done by putting in a heating loop into the air ducting that is shared with the air-pump. This could be a compact fan assisted system. There would be expense in heating controls for all the ducting. However, if you cannot put in ducting, then you can install a water radiator central heating system. To work with a heat pump, you can go for the super-efficient CO2 based systems that are emerging but expensive. The efficiency can be raised if the heat is needed at a low temperature, so requiring either under-floor heating or a 'fan assisted radiator' which extract more heat and can return the water to the heat pump much cooler than normal radiators, and require a lower temperature, raising COP. I would go with: Waste water heat exchanger ( I guess $500 est with capital cost $200-$300 plus basic installation if incorporated with a boiler installation and pipework anyway) -this will reduce the energy requirement of the condensing boiler, potentially allowing a smaller system. Condensing boiler - 15-25kW output, 90% efficient, capital cost $500 ebay Air-to-Air heat pump (in loft) - COP 3-5 (later figure seen in an Austrian GSHP but should work with airsource unless outside air is usually very cold?) cost? controls? Fan assisted radiator in ducting for backup (run off boiler)? Ventilation heat recovery

Since you have chosen warmboard over gypcrete, what was your reasoning behind it besides responsiveness? I am sorry for the confusion. I didn't build a house with Warmboard, I had it in a house where original owner had installed it. It wasn't a house I built. I used it in the sense that I heated the house with it. I looked at the Gypcrete system and somehow feels uneasy about it. Doing a concrete pour over first and second floor does not sound structurally sound to me. Gypcrete has positives and negatives but shouldn't be overlooked because of structurally sound. I think a competent and knowledgeable designer is much more important than which type of system you use. So if you don't have a lot of experienced local people, you have to find experienced people who can help design at a distance. I would start with Radiant Engineering (talk to many companies though). A long somewhat unbiased discussion of radiant: First, it should be noted that radiant heat isn't an efficiency discussion. As people have pointed out many times hydronic radiant systems rarely have a positive payback. They are simply too expensive to install and they never payback if you are installing central air. However, every decision in your house isn't about payback. There are many decisions, such as paint color, cabinet color, cabinet design, many fixtures, etc., that are about your enjoyment of your home. No one has a pool installed because they want it to add value to their house. Radiant fits soundly into that category. Next: A discussion of trade-offs between the different systems. It is important to note that ALL radiant floor systems will provide a comfortable environment to a home that other heating methods struggle to achieve. There are basically five considerations in radiant heat (1) installation costs, (2) operating costs, (3) responsiveness (4) allowable customization and (5) noise (as hot water passes through cold aluminum plates it makes noise). If we look at the different systems we can typically see how they handle each of these things. Warmboard is (1) very expensive to install, (2) it has a low operating cost as it is a warm water system rather than a hot water system, (3) incredibly responsive for radiant heat (able to heat a structure in hours rather than days), (4) low customization and (5) low noise. Underfloor transfer plate systems are (1) moderately expensive to install, (2) low operating costs as they are also warm rather than hot water systems, (3) are somewhat responsive (4) highly customizable and (5) have more expansion noise. Gypcrete overpour is (1) moderately expensive (still cheaper than the two above), (2) have low costs as,they too are warm water systems, (3) not responsive at all, (4) are highly customizable and (5) eliminate almost all noise. Staple up systems are (1) pretty cheap (2) high operating costs as they are a hot water system, (3) not responsive at all, (4) limited customization (they are more limited by physics than design), and (5) are pretty noisy. So looking at Warmboard vs. similar systems - the only real concern from using any aluminum covered plywood system is the noise. Warmboard eliminates expansion noise because of the "special" glue they use to adhere the aluminum to the wood. I can't really tell you how special their glue is, I feel confident they will say super special and their competition will disagree. Warmboard type systems vs. underfloor transfer plate systems - Warmboard is quieter but the loops are not really customizable. Loops are 8" apart with Warmboard, so you can choose not to put warmboard in places but you can't get the loops closer together. With transfer plate systems you can customize the heat of a room by simply moving the loops closer together. This means that you can make the floor right outside the shower warmer than the floor beside the toilet (not many people spend a lot of time standing beside their toilet), but there is more expansion noise. Warmboard is a bit more responsive than transfer plates. Warmboard vs, gypcrete overpour - Gypcrete overpour gives you almost unlimited customization without the noise associated with aluminum transfer plate systems. However, it is not at all responsive. Staple up systems - They are more expensive to operate than any of the above systems but are cheaper to install and easier to maintain. You are not likely to nail through a staple up system with a nice thick transfer plate. Also easier to remodel with staple up systems. TL:DR In the end, if I was ranking a radiant system today - I would probably rank it - underfloor transfer plates > gypcrete > Warmboard. But it is a three way photo finish so it wouldn't take a lot to change the order. Also noisy houses don't bother me at all.