The best hot water system for an Airbnb or holiday rental depends on guest numbers, bathrooms, peak usage times, fuel source, installation space and running costs, not just the number of bedrooms on the listing. Hot water systems built for guest accommodation need to work differently to a system in a normal household, and getting the sizing wrong is one of the fastest ways to end up with a bad review.
For Airbnb and holiday rental owners, hot water systems are part of the guest experience. A cold shower on a Saturday morning doesn’t just annoy one guest; it shows up in a review that future guests will read before they book.
Guests expect hot water systems to work without instructions. They won’t check a manual, adjust a timer, or know that the tank needs twenty minutes to recover after three showers. If something goes wrong, most hosts aren’t onsite to fix it, and a failed hot water system mid-booking can mean refund requests, awkward guest messages, and a scramble to get a plumber out before check-out.
Holiday rentals also tend to have concentrated usage windows. Everyone showers around the same time in the morning, after a day at the beach, or before dinner, which is exactly when hot water systems come under the most pressure. That’s a very different demand pattern from a household where people are in and out of the bathroom throughout the day.
Sizing a hot water system around bedroom count or the previous owner’s habits can leave a property under-supplied the moment it starts hosting guests.
Back-to-back showers. Families and groups getting ready together, especially before dinner reservations or day trips, put far more pressure on a system than the same number of people would in a typical household routine.
Higher peak demand. A house that might normally have two occupants can suddenly host six to eight guests during a long weekend or school holidays, and the hot water system still has to keep up.
Extra appliance use. Cleaners running a load of towels between bookings, guests using the washing machine, and general turnover activity can all land in the same window as guest showers.
Less user control. Guests don’t know your system, whether it’s on a boost setting, an off-peak electric system that needs time to reheat, or a storage tank close to empty after the last shower.
Before locking in a system, work through the factors that actually affect performance for hot water systems in a short-term rental:
A one-bedroom city apartment with two guests has very different hot water needs from a coastal holiday home sleeping eight people, with two bathrooms, a laundry, and an outdoor shower. Sizing both properties the same way is how complaints happen.
Sizing should always be confirmed with a licensed professional, but the general principle is to size hot water systems for the busiest realistic guest occupancy, not the average booking.
Storage water heaters are sized by litre capacity. As a general guide for electric storage systems:
| Guest capacity | Typical electric storage size |
| 1 to 2 guests | 125L |
| 2 to 4 guests, 2-bathroom home | 250L |
| 5 or more guests | 315L |
| High-use short-stay properties | 400L |
Continuous flow systems are assessed differently, based on flow rate rather than litres, since they heat water on demand rather than storing it. More outlets running at once, such as two bathrooms and a kitchen tap during a busy turnover morning, means the unit needs a higher flow rate to keep up.
More guests and outlets increase demand, and a system should always be chosen for peak usage rather than a quiet weekday. Undersizing leads to guest complaints, while oversizing increases both the upfront price and the running costs for water that’s heated but never used.
| Property type | Typical concern | Possible system direction |
| Studio or 1-bedroom Airbnb | Low guest count, limited space | Compact electric, gas or continuous flow unit |
| 2 to 3-bedroom holiday unit | Families, back-to-back showers | Larger storage system or a correctly sized continuous flow unit |
| Large holiday home | Multiple bathrooms, groups, peak demand | Higher-capacity storage or a multiple-unit solution |
| Remote or high-occupancy rental | Reliability and fast recovery | Professional sizing, a durable unit, and planned maintenance |
Electric storage systems are used by around half of Australian households, and standard electric storage systems remain among the cheapest hot water systems to buy and install. An electric hot water system suits apartments, units and smaller holiday properties well, provided the storage tank capacity is matched to guest demand. Common sizes for electric storage systems range from 125 L to 400 L.
Without solar, electric storage tanks generally have higher running costs than a heat pump system, since the electric booster is the main energy source. Some hosts switch to an off-peak tariff to save money, though this needs careful sizing for a holiday rental, since guests won’t necessarily shower during the cheaper overnight window.
Gas hot water systems can offer strong recovery between uses, provided there’s a natural gas supply or LPG bottles at the property, and the system matches the property’s existing fuel type. They’re generally installed outdoors and suit properties with existing gas infrastructure.
Gas storage tanks have higher heat loss than insulated storage tanks on a heat pump or electric system, since it isn’t possible to fully insulate the tank while the gas flame heats it. As a result, these gas hot water systems tend to fall into the medium-to-high range for running costs. In hot weather, this matters less, but in cold climates, it can drive up energy bills during a busy season.
An instant gas system or an electric continuous-flow hot water system heats water as it’s needed rather than storing it in a tank, removing the classic “ran out of hot water” scenario that underlies so many complaints about cold showers. The catch is that the flow rate must match the number of outlets in use at once, since multiple showers running simultaneously require sufficient water pressure to keep every guest comfortable.
A unit sized for one bathroom will still struggle if two showers and a kitchen tap run during a busy check-in morning. When sized correctly, continuous-flow hot water systems suit space-saving, high-turnover properties, though maintenance requirements can be slightly higher than those of a simple storage tank.
A heat pump hot water system extracts heat from the surrounding air rather than generating it directly, and it uses up to 75% less electricity than standard electric storage for the same amount of hot water.
That energy efficiency makes a heat pump system a highly efficient option for hosts trying to reduce energy bills on a property booked most of the year. Heat pump hot water systems provide reliable mains-pressure hot water and, paired with a solar PV system, can run largely on electricity already generated on-site, saving energy and cutting overall energy use. The trade-offs are the noise as the compressor switches on and off, and the fact that a heat pump can still run out of hot water and take time to reheat under heavy guest demand.
Rebates for heat pump systems are available in some states, offsetting the higher upfront cost.
Solar hot water systems use solar collectors or panels on the roof to heat water with solar power and, in the right conditions, can provide up to 90% of a household’s hot water needs. Solar PV paired with a booster is another way to generate the electricity that heats stored water, and both approaches offer long-term energy savings in sunny climates, saving at least 60% more energy than conventional systems over the system’s life.
Installation costs are generally higher than electric storage or gas, and a solar system will usually need a gas or electric booster for cloudy stretches or when guest demand outpaces what the panels alone can cover.
For coastal holiday homes with good roof access, solar can be a genuinely efficient way to save money on energy bills, though it’s worth discussing booster capacity and water quality if the property sees high occupancy during the cooler months.
Water heating is one of the bigger ongoing costs for any holiday home, so running costs are worth weighing alongside upfront price. Gas systems generally fall in the medium-to-high purchase price range, and gas supply availability at the property often determines whether a gas hot water system is even an option.
A heat pump hot water system with a well-insulated tank loses less heat between uses than an uninsulated gas storage tank, which helps lower energy bills across a full booking calendar, and pairing a heat pump or solar PV system with existing solar panels is one of the more effective ways to reduce costs on a property that runs hot water most days of the year. Matching the system correctly to guest numbers is what actually drives the savings, more than the fuel type itself.
If the system has failed during a booking window, speed matters. Same-day advice, supply and installation can help reduce disruption and get the property guest-ready again before the next check-in.
Not every Airbnb needs a commercial-style setup. Most studios, standalone houses and small holiday units are well served by a correctly sized residential electric, gas, heat pump or solar hot water system. But larger properties, boutique accommodation, multi-unit rentals and consistently high-occupancy stays can behave more like a small business than a home, and the decision should come down to actual demand, outlets and recovery rate rather than the property type on paper.
If your property operates more like guest accommodation than a standard home, it’s worth getting advice on a business or commercial-style hot water setup rather than stretching a residential system beyond what it was built for.
Same Day Hot Water Service can help owners choose, supply, install, repair, or replace hot water systems for Airbnb and holiday rental properties, with support available Australia-wide, including Sydney, Melbourne, Brisbane, Perth, Newcastle, Central Coast, Wollongong, the Sunshine Coast, Canberra, and the Gold Coast.
Need a reliable hot water system for your Airbnb or holiday rental? Contact Same Day Hot Water Service for expert advice, upfront pricing and fast installation before your next peak season.
There’s no single best system for every holiday house. The right choice depends on guest capacity, bathrooms, fuel source and installation space. A well-sized electric storage, gas storage, continuous-flow, heat pump, or solar system can all work well when matched correctly to peak guest demand.
Airbnb doesn’t supply hot water systems directly. As the host, you’re responsible for making sure the property has a working, appropriately sized hot water system installed by a licensed professional before guests arrive.
Airbnb doesn’t set a fixed technical standard requiring hot water at every listing. Hot water is a self-selected amenity, originally meant for remote or off-grid properties where it can’t be guaranteed. In practice, guests assume hot water is included almost everywhere, and a property without it reliably leads to complaints and refund requests, whether or not it was formally listed as an amenity.
It usually means the existing system has failed, was undersized for guest demand, or hasn’t been serviced regularly, and it’s a booking disruption risk worth addressing before it happens rather than during an active stay.