Updated October 2026
St Andrews Beach is back-beach country behind the dunes south of Rye, a low-density mix of newer architectural houses and older holiday places set among tea-tree, with golf links and the national park nearby. Blocks are large and heavily vegetated. Mornington Hot Water is a free referral service. We connect you with licensed hot water plumbers who cover St Andrews Beach. We are not a plumbing business ourselves, and the referral costs you nothing.
Newer houses, bigger systems
The newer builds here tend to have multiple bathrooms and serious peak demand when a full house arrives, so sizing matters more than it does in a two-bedroom shack. A 26L/min continuous flow unit or a large storage system is common, and undersizing shows up immediately when three showers run at once.
Tea-tree cover is the system constraint. Solar hot water needs an unshaded north-facing roof and very few blocks here offer one, so heat pumps and continuous flow dominate the low-running-cost conversation.
Exposure and seasonality finish the picture. Back-beach wind carries salt and sand, which wears external units, and houses used seasonally suffer the idle-tank failure that is common right across the southern Peninsula.
Repair it or replace it
If the tank itself is leaking, it is a replacement. Elements, thermostats and relief valves on a younger tank are often worth fixing, with repairs roughly $150 to $600 depending on the part. See hot water repairs and hot water replacement.
As a guide, electric storage like-for-like swaps run from around $800 to $2,500 installed. Gas storage and continuous flow sit around $1,200 to $3,500, and a heat pump $3,000 to $6,000 before incentives. Mains gas availability varies by address. The cost guide has the detail.
Same-day replacement is often possible for common tank sizes when you get in touch in the morning.
Frequently asked questions
What size continuous flow unit does a four-bathroom house need?
Usually 26L/min, or a twin arrangement for very large households. The plumber sizes it from simultaneous use rather than bathroom count alone.
Does sand affect outdoor units?
Blown sand and salt together wear casings and fins. A sheltered position and an occasional rinse help.