Gas boiler replacement · Auckland
Vaillant ecoTEC plus condensing boilers — 15, 25 and 36 kW.
The underfloor pipework in your slab is built to outlast the boiler, so replacing a boiler does not mean lifting the floor. Most replacements are done in a day. A condensing boiler on a low-temperature underfloor system runs at its highest efficiency.
Why Vaillant
We fit Vaillant ecoTEC plus boilers on hydronic underfloor systems mainly because of how low they can turn down.
A heated slab needs a small, steady amount of heat for most of the winter. A boiler with a high minimum output (say 8 kW) switches on, overshoots, switches off and repeats. This is called short-cycling, and it wastes gas and adds wear. The ecoTEC plus modulates down to 2.8 kW, so it can run steadily at low output.
A condensing boiler recovers heat from its exhaust gases, and recovers the most when the water returning to it is cool. Underfloor heating returns water at around 30 °C, which keeps the boiler condensing.
42–47 dB(A), depending on model.
All three models are 440 × 720 × 348 mm and weigh 34–39 kg. In most replacements the new boiler goes on the same wall and uses the same flue position.
Vaillant’s IoniDetect system adjusts combustion automatically to suit natural gas or LPG and variations in gas quality.
Vaillant boilers are supported in New Zealand, and spare parts are available locally.
The range
All three are the same size and mount the same way. The right size comes from a heat loss calculation for the house, not from the size of the old boiler, which was often larger than the house needed.
Suits most Auckland houses with underfloor heating only. It modulates down to 2.8 kW for steady, low-output running.
The model we fit most often as a replacement. The same 2.8 kW minimum as the 15, with a higher maximum for larger houses, a stored hot water cylinder, or underfloor plus radiators.
A combi boiler: it heats the house and heats hot water on demand, so no hot water cylinder is needed. Suits larger homes, or where the existing cylinder needs replacing and the space is wanted back.
Boilers we replace
We replace all brands of hydronic boiler in Auckland. In almost every case the underfloor pipework, manifold and thermostats stay as they are.
How a replacement goes
Boiler, flue route, gas supply, cylinder, manifold, controls and the condition of the system water. Plus the heat loss calculation, so the new one is sized for the house rather than for the old boiler.
A condensing boiler and, where suitable, a heat pump alternative, with installation and running costs for each.
The old boiler is removed, the system is flushed and treated if needed, the new boiler is fitted, the flue and condensate drain are completed, and the gas work is certified. Usually done in a day.
Flow temperatures are set for underfloor heating rather than left at the factory default, every zone is checked, the controls are set up, and we show you how to use them.
Pricing
The installed price depends on the flue, the gas work, the controls and the condition of the system water, so we price each job individually. Tell us what you have and we will send you a fixed price.
Questions
We try to repair it first. Most faults are a sensor, a pump, an ignition fault or a blocked condensate drain. Replacement becomes the better option when parts are hard to get, when the boiler has needed several repairs, or when it is an older non-condensing model using more gas than necessary. We can price the repair and the replacement side by side.
No. The pipe loops in the slab do not wear out and are not what has failed. In almost every boiler replacement the loops and the manifold stay as they are; only the boiler is replaced.
An older boiler loses a large share of its heat up the flue in hot exhaust gases. A condensing boiler has a second heat exchanger that recovers that heat by condensing the water vapour in the exhaust, which is why it needs a condensate drain. The gain is greatest when the water returning to the boiler is cool, which is what underfloor heating provides.
A heated slab needs a small, steady amount of heat for most of the winter. A boiler that cannot turn down below about 8 kW switches on, overshoots, switches off and repeats. This short-cycling wastes gas and adds wear. The ecoTEC plus modulates down to 2.8 kW, so it can run steadily at low output.
A system boiler heats the house and a stored hot water cylinder. A combi heats the house and heats hot water instantly as you use it, with no cylinder. If your cylinder is in good condition, a system boiler usually makes sense; if it needs replacing and you want the space back, a combi. Household size and how many showers run at once also affect the choice.
Both. The same models run on either; outputs differ slightly at the low end. Much of Auckland has reticulated natural gas; outside those areas it is bottled LPG. Tell us which you have and we will specify the boiler to suit.
Vaillant equipment carries the manufacturer’s New Zealand warranty, and the term depends on the model and on registration by the installer. We confirm the exact term in writing on your quote rather than quoting a headline number on a web page. Our own workmanship is guaranteed separately.
Sometimes. A heat pump usually costs less to run and has no gas connection charge, but costs more to install and needs space outside. A condensing boiler costs less up front, connects to the existing gas supply and fits in the same space as the old one. We can price both, with installation and running costs, so you can compare.
A like-for-like replacement in the same position usually takes a day. It takes longer if the flue route has to change, the gas supply needs upgrading, or the system water needs flushing and treating first.
Gasfitting is certifying work in New Zealand. The gas work on your boiler is carried out and certified by a licensed gasfitter, and you receive the gas certificate.
Specifications are the current manufacturer figures for the New Zealand market and are subject to change without notice. Champion Heating is an independent installer; Vaillant is a trademark of Vaillant Group.