Gas hot water conversions and installation in Christchurch

What a gas hot water conversion is

Most Christchurch houses still heat their water in an electric cylinder: a tank in a cupboard that is kept hot around the clock whether anyone is using it or not. A gas conversion replaces that with a continuous flow gas water heater mounted on an outside wall. It heats water only as it passes through, so there is no tank to keep hot and no tank to run out of.

• You don't run out. Back-to-back showers, a bath and the dishwasher: the unit keeps heating as long as the tap is open.
• Mains pressure hot water. Continuous flow delivers hot water at the pressure of your cold supply, which is why a conversion often fixes a weak shower as well.
• The cupboard back. With the old cylinder gone, the hallway cupboard is a cupboard again. In a small Christchurch bungalow that is often reason enough.
• Works on LPG or natural gas. No gas at the street is not a problem: a pair of 45 kg LPG bottles runs it.

What's involved in a conversion

1. A site check first. Where the unit can go, how far the gas and water runs are, and the clearances the flue needs from windows, doors and the boundary. That is what the quote is built on.
2. The gas supply. A natural gas connection where there is one, or two 45 kg LPG bottles on an automatic changeover regulator, so when one bottle runs out the other takes over and you don't lose hot water halfway through a shower.
3. A gas line sized for the unit. A continuous flow water heater uses far more gas at full flow than a hob, so the pipework has to be sized for it. Undersized gas pipe is the most common reason a unit struggles.
4. Water connected to the unit and the hot water run to the house, with the old cylinder disconnected so the cupboard can be cleared.
5. Power for the unit. Continuous flow units need a power point nearby for their ignition and controls. If there isn't one, it needs an electrician, and we'll tell you at the quote stage.
6. Tested, commissioned and certified. Pressure test, flame and temperature checks, and a gas safety certificate for the installation. We issue the certificate ourselves.

LPG bottles or natural gas?

Natural gas is generally cheaper to run and there are no bottles to swap, but only if there is a connection available at your property. Getting gas to a house that has none at the boundary is a separate project.

LPG works anywhere: the hill suburbs, out towards Rolleston, or any street without reticulated gas. Your gas supplier delivers and swaps the bottles, and the automatic changeover means you only notice when it's time to order. Per unit of energy it costs more than natural gas, and that is worth knowing before you decide.

On a bottle set-up, the pigtail hoses between the bottles and the regulator should be checked and replaced every five years or so. There is more on that on our certifying gas fitter page.

Is gas hot water right for your house?

It suits most homes that use a fair amount of hot water, households that keep running out, and anyone who wants the cylinder cupboard back. The honest trade-offs:

• Running costs depend on your gas. Bottled LPG costs more per unit of energy than electricity does for a cylinder, so the running cost comparison depends on how much hot water you use and whether natural gas is available. We'll give you the real comparison rather than the sales version.
• Long pipe runs mean a short wait. Where the unit sits a long way from the bathroom, hot water takes a few seconds longer to arrive. Placement is part of the site check for that reason.
• Size matters. Units are rated by how much hot water they can deliver at once. Two showers running together needs a bigger unit than a one-bathroom house, and we size it to how you actually use water.

If gas isn't the right answer for your place, a mains pressure or heat pump cylinder might be, and we'll say so. The options are compared on our hot water cylinder page.

Gas water heater installation and replacement

Already on gas? We replace old continuous flow units and califonts, swap a failed unit for a current model, and move or re-flue units that are in the wrong place. Outside units on the coast corrode faster in the salt air, so in Sumner, Redcliffs and the eastern bays a tired-looking casing is worth having looked at before it fails. Every replacement is tested and certified the same as a new installation.

What it costs

Every conversion is different. The unit, the gas supply, the length of the pipe runs and where the old cylinder sits all move the price, so we quote it properly after a look rather than guessing over the phone. Quotes are free in Christchurch, our pricing is affordable and competitive, and what we quote is what you pay, with the gas certificate included. Repairs to existing gas water heaters are charged at our published hourly rates.