There is a problem with the electric resistance heating and its sequential operation. With all breakers ‘On’, the backup should active automatically WITH the HP (compressor ‘On’) when a demand for backup is called. This should be when either the temperature of the house drops 2-degrees or more below the set point or when the HP compressor has been running continuously for a pre-programmed period of time, that could be 45-minutes or more. Then backup comes on with the HP compressor. When the thermostat demand has been met everything shuts off and resumes ‘normal’ operation with the next demand, that is HP no backup. Emergency Heat should be electric backup no compressor, just blower. These issues are strictly electrical, programming of thermostat and HP control board. I don’t know what city you’re in or near so I can say what the ‘design temperature’ should be. I’ll make some assumptions about your system based on the information provided. It’s a 2-1/2 ton HP, 4- pipe linear horizontal non-pressurized ground loop with no expansion tank and a ‘QT’ Flow Center. As such, being non-pressurized, there is a reduced likelihood that the horizontal loops have lost contact with the ground due to contraction as a result of reduced temperature. However, it is important that you verify that the antifreeze level of the fluid in the ground loops is at least 20% as it would be quite normal that fluid level temperatures, particularly Leaving Water Temperatures (LWT) could be 25 degrees Fahrenheit. These (normal) temperatures below freezing might put your ground loops at risk of bursting should they freeze. That would be a disaster! Other issues are that your ground loops may loose contact with the earth during a prolonged dry spell. It is normal and highly desirable to have all ground loops installed with a ‘Soaker Hose’ or line and a HP selected that can monitor this condition and when called for activate a circuit, usually a solenoid, to turn ‘On’ the ‘Soaker Line’ to automatically rehydrate the earth so that the HP can resume ‘Normal’ operation. Does your system have a ‘Soaker Line’ buried below the frost line? Based on what you’ve indicated about your system operating properly when ‘fixed’ I’ll assume for now that your ground loops are sized correctly. Another factor that might be in play here is, is the flow rate high enough to generate ‘Turbulent Flow’? You need a contractor that knows about this and can verify the ‘Reynolds’s Number’. Basically, what you need is a flow rate of at least 3-gpm/ton to achieve turbulent flow and complete mixing of the circulating fluid in the ground loops. If flow rate drops below this figure, what you have is ‘Laminar Flow’ where the circulating fluid stratifies in the ground loops, circulates in a linear fashion as opposed to a turbulent fashion, and does not pick up all the heat from the ground that it was designed to. It is for these reasons that I recommend the flow meter linked to below. This device will allow you to verify the flow rate and unlike a straight gauge like a circular temperature or pressure gauge, will allow you to see the fluid and watch for air bubbles that will impede the flow, reduce the heat transfer and possibly degrade the impeller on the flow center circulator pump (which should be verified as well). However there is a reduced likelihood of bubbles in the system with the ‘QT Flow Center’. Does your system have a ‘Desuperheater’? If so please discribe it along with the buffer tank configuration and plumbing. SR Here is a link that might be useful: Flow Meter

Sara, Ion beat me to it and gave you some good advice. I'll offer a bit more clarification on some questions you may have. It is a little difficult, as it's hard to discern how much knowledge you have in this area. I don't want to offer information which would be redundant to you. "1) Grounding of the furnace My generator's ground is connect to the ground prone of three prone plug(other two prone are not connected) through a 12 gauge wire and plug into an outside wall outlet. Is this good enough grounding for the generator? if I plug the furnace wire into generator, is this good enough grounding for the furnance?" Assuming you are simply using a pigtail on your furnace, as Ion mentions, do not connect your generator to any of your house wiring system. I would treat the system as simply a portable generator system for NEC purposes. Namely, simply plug your three prong pigtail into a three prong extension cord and plug your three prong extension cord into your three prong recep on your generator. No ground rod is required. Lastly, make sure the neutral in your generator is bonded to the equipment ground and the generator frame. Most generators are set up this way, but some aren't. It should say in your generator manual, but also do a check to make sure. You should see a wire bonding the generator to its frame. You should also see a jumper bonding the neutral to the equipment ground, but you may have to take off a cover to observe this. Your generator should have GFCI for the 120V receptacles. You don't need any other ground protection than this. Remember it's really the neutral that protects one against most faults which could cause electrocution. What most people call the "ground" is really a case ground (or equipment ground) which is ultimately "bonded" or connected to the neutral at some point. It's the "bond" of the neutral and case ground which really provides the fault protection when voltage leaks to the case. A ground rod doesn't really provide any protection in this sense. Let me give a real world example (I hope I'm not offering info. redundant to you here.) Decades ago, before case grounds (or equipment grounds) were installed on refrigerators, people were sometimes electrocuted from them. What happened was this. The refrigerator had a two prong plug - one for the lead, and one for the neutral (i.e. return current). The refrigerator would get old, wires would fray, or the motor would start leaking voltage. A lead wire would touch the case, or the motor would leak enough voltage the case/housing of the refrigerator would become energized. Maybe from time to time one of the family members might notice the refrigerator would "shock" them. It wasn't a bad shock, because the impedance was too high for the return path from the case through the persons body to the neutral. In other words, the path of electricity wasn't a good connection. They had shoes insulating them, etc. One day one of the family members, while getting some milk out of the refrigerator, spills some on the floor. It's early in the morning, so they're in their bare feet. They mop the milk up, but the floor is still wet. They grab the handle to put the milk back, but now the impedance is much lower (the combination of a wet floor and bare feet make a much better path for electricity). The current flowing through the person causes a constriction of the hand muscles. They can't let go of the handle. They can feel they are being electrocuted, but there is nothing they can do about it (by themselves). After a few moments, the same current causing constriction of the hand muscles makes the heart labor to keep it's rhythmic beat. After a short period, it stops beating altogether. By installing a case/housing ground (i.e. the third prong on the plug) a low impedance grounding conductor provides a direct short in the circuit if there is a lead fault in the refrigerator housing. The path would be from the lead, shorted to the case, through the case ground wire, back the the main panel, where in the main panel, the neutral and the case ground buses are bonded (connected). This direct short will "pop" the breaker, or blow the fuse. So long as the third prong on your pigtail is grounded to the case of the furnace, and the neutral and case ground are bonded on your generator, you won't be electrocuted from your furnace. You could still be electrocuted from your extension cord lying in a water puddle, or wet from rain if the outlet on your generator isn't gfci, but all newer generators are supposed to have gfci receps. "Why all this precaution when it comes to wiring the furnace, like separate circuit?" NEC requires all stationary appliances to be on their own circuit. So the main answer to your question is that it's code. The reason for the code requirement is to avoid people putting a lot of appliances on one circuit, causing the breaker to trip. Let's say you have your refrigerator, deep freeze and furnace on one circuit. One day the breaker trips rendering all three appliances dead. It normally happens when you are on vacation, so you come back to your house with all your food spoiled and your pipes frozen/broken. As a bonus, the water thawed enough to run for three days, flooding your house. NEC code allows an exception for any associated furnace equipment (humidifier, condensation pump) to be included on the same dedicated circuit as the furnace. "Olpea mentioned electricity generated by generator is of poor quality and can damage furnace. a 20 amp surge protector can prevent the damage to furnace from happening, right?" Unfortunately surge protectors really do very little in this regard (I'm referring to the surge power strips). A good one will prevent a major surges until the material inside is "consumed". This can happen with one surge. They won't prevent voltage drops. They also do nothing to correct sine wave distortion and frequency stability, which are also hard on electronics. My main point was not to try to talk you into a new generator but to keep your generator lightly loaded if you need to run electronics like your furnace. That will at least provide more stable voltage. Re: Inverter generators When I mentioned inverter generators, I was thinking of high quality Yamaha or Honda inverters, which are pure sine wave inverters and known for producing the cleanest power. Ion is correct, cheap inverters produce a poor waveform (as do cheap non-inverter generators). I disagree with Ion that electronics are not sensitive to power quality. I believe the opposite to be true. This post is a lot longer than I intended. Didn't mean to write a book.

As I understand it, you're asking to create an extension cord from your RV, with both 240V and 120V outlets. You would unplug the pump from the house, and into the RV "extension cord". In this way, there's no way for the house power to be connected directly to the RV. I don't know of any way that you can provide both types of circuits (240 and 120) according to the NEC unless you install a sub-panel. However, to install wiring for just the pump, you could do this with 10 gauge 2-wire (plus ground). If you use UF cable, bury it to a depth of 24". Alternately, use individual 10 gauge THWN installed in conduit buried to a depth of 18". Then, at the outlet (and plug) end, simply hook the two conductors to the screws on the outlet (or plug) (the two conductors can be attached to either point). Connect the ground to the outlet (and plug), and also to the junction boxes if they are metal. There is no neutral in this circuit, and therefore no 120V power is available. If you decide to install a sub-panel, you'll need to use 3-conductor (plus ground) wire. Please see the FAQs at the top of this site for more information. Just make sure that whatever you do, that there's no way for the RV output to be connected to the house power.

People do stupid and dangerous things all the time. To some degree that's why the electric code exists, to protect people from themselves. There's plenty of hazards in the situation you describe -- from the risk of equipment damage, fire, personal injury, and even death. This guy may get lucky do this for years without problems. One day maybe he's had a couple of beers or just a lousy day and forgets to flip those breakers. Or maybe he's at work and his wife or kid thinks they know what to do. Then somebody is at the hospital or worse. Do it the right way. The life you save may be your own.