Look in your gray/black tank bay (curbside in front of rear tires, with door latches underneath), and on the ceiling you should see a heat exchanger. On ours, its bay temp sensor probe is mounted on a black plywood square frame center front on the bay floor, along with an Aladdin module. As long as the HydroHot is on, the exchanger kicks on at a bay temperature around 43 degrees or so.
The water pump mounts in a plastic housing that extends into that bay, but is accessible via a panel in the adjoining bay's wall. Heat can flow into the housing, over to the back of the water bay manifold, and over the adjoining bay wall, but the inverter on the main bay's ceiling adds a little heat there also, and the HHot unit itself in the frontmost bay warms the water tank next to it. We have bays on the streetside that are unheated, and the tiny bay behind the rear tires, so I'm careful what's in there in cold weather.
Don't always depend on the HHot electric side only, as if there's a power outage while you're asleep or away you risk a bay freeze up. Usually it's okay as long as outside temps don't stay low for long periods, and warm the next morning, but keep the diesel side on anyway during cold snaps.
Inside we supplement with a small electric heater toward the back so the noisy front exchangers don't run as much while we're conversing or watching TV. Overnight it's set up front on low. It uses electricity we have usually already paid for with park fees, and cuts down the diesel HHot use. Just be mindful of your total amp use so you don't trip breakers when some other device kicks on.
We also occasionally use, in very cold weather, a "wool" covered thick foam square as an insulator that presses up into the kitchen Fantastic Fan vent port, especially overnight. We don't use it in the bathroom fan and may keep that vent cracked a bit together with slightly cracked window elsewhere to help prevent frosting from built-up humidity. We don't need to do that often, though, thanks to the double-pane windows and defroster fans over the windshield. We often trap a large, folding, reflective silver windshield cover between the windshield and its lowered electric sunvisors, especially during sub-freezing overnights. In addition to the regular privacy curtain, it offers some insulating benefit. In summer it helps reflect solar heat out.
Of course you don't want to leave a water hose hooked up outside; just use your tank's supply and refill it as needed. If necessary you can get hoses that are heated, but my agenda doesn't hold value in the cost. Be aware that if it snows, the stuff can build up on slideout awnings and add to the material's bellying problems. If it thaws incompletely during the day, then freezes overnight, you'll have a layer of ice too. This can jam the material upon slideout retraction and cause problems, including stressing mechanisms and motors/pumps. I try to keep snow swept off, but walking on a slick roof is not for the weak of heart; it's safer with a broom and a folding ladder against the slideout. Ice is not so easy to get off. Once when heavy snow was forecast, we kept the slides in until it quit.
Joel
