Hot water tank failed? Replace like-for-like, or upgrade to heat pump?
Tank's leaking, ceiling's stained, the house is cold. You've got maybe 48 hours before this becomes an insurance claim and a mould problem. The installer on the phone is asking: like-for-like gas swap, or upgrade to a heat pump? Here's how we'd answer.
The 5-minute decision matrix
| Scenario | Recommendation |
|---|---|
| Rental property, owner pays bills | Heat pump (rebate + lower bills) |
| Rental, tenant pays bills | Like-for-like gas (no benefit to owner) |
| Owner-occupied, no solar, gas connected | Heat pump |
| Owner-occupied, solar PV installed | Heat pump (daytime schedule) |
| Holiday house, used <30 days/year | Like-for-like gas |
| Townhouse with shared gas line, no roof access | Heat pump |
The maths
Like-for-like 135L or 175L gas tank replacement: roughly $1,800–$2,300 installed. No rebate, no STCs. You're back to the same annual gas + standby loss costs as before.
Heat pump 270L upgrade with VEU applied: roughly $1,780–$3,500 installed (Thermann–Reclaim range). Plus you save $400–$900/year on energy. Payback is 2–4 years.
For most owner-occupiers, the heat pump is cheaper in 24 months. The gas swap only wins if you're stuck with no roof space, no eligibility, or a holiday rental.
Same-day swap reality
We carry the common gas tank sizes (135L and 175L) on the truck for emergency same-day replacements. Heat pumps need ordering and certifying, so expect 3–5 days for a heat pump swap — but we'll fit a temporary hot water solution while you wait.
If it's Friday afternoon and you want to be off the gas grid by Monday, the heat pump path is faster than people think.
FAQ
Do I lose my rebate if I do the gas swap first?
No — VEU eligibility applies whenever you eventually upgrade. But you'll have spent ~$2k on a gas tank you're then replacing in a few years.
How long does a temporary hot water setup last?
We can fit a small electric storage unit or rent a portable instantaneous for 5–7 days while heat pump stock arrives. About $150–$250 extra. Removes the pressure.
Will my gas bill drop if I switch?
If hot water is your only gas appliance, your gas account can usually be disconnected — saving the supply charge (~$300/year). We can advise on whether to keep gas connected for heating/cooking.