Q. Do solar power systems work when the sun isn't shining?
The Vaillant solar domestic hot water system is able to work even on cloudy days because it uses diffused radiation as well as direct sunlight.

Q. How much can I save by reducing my heating and water temperatures?
Reducing your room temperature by 1ºC could cut your heating bills by 10%. Setting your water cylinder temperature to less than 60ºC and fitting approved thermostatic mixing valves will also help save money.

Q. Are there now more sophisticated ways of programming heating than a thermostat and timer?
Yes, more intelligent heating controls are now available that can increase your comfort and save energy.

For example, wireless heat controls in every room can be reset remotely from your laptop – very useful if you have an irregular schedule.
Weather compensation controls do just what they say by monitoring the outside temperature and the room temperature using Vaillant’s VRC 400 or VRC 430 controls, and then adjusting the boiler to achieve the required heat output. On a sunny day for example, the heat output from the boiler will be reduced, as a result radiators may feel cool to touch.

Q. I’m extending my home – will I need a new boiler for the new section of the house?
The capacity of your existing boiler will have been matched quite closely to the size of your home – the floor space and the number of bathrooms – in order to achieve maximum efficiency. If you are just adding one radiator for a new conservatory you will not need to replace your boiler, but if more radiators and hot water are required you should contact a heating adviser to find out if a new boiler is needed.

Q. What is the ultimate low-carbon energy saving system that’s available today?
Ground source heat pumps run almost entirely on non-fossil fuel. They extract the earth’s natural heat using electricity that can be supplied by a renewable energy source such as solar power. The pumps have much lower running costs than oil, coal or electric heating systems and will cut your CO2 emissions by between 4.5 and 5.5 tons of CO2 a year.

Meanwhile, a solar water heating system can reduce CO2 emissions by 350 to 400 kilograms a year, depending on which fuel type it replaces.

Q. Are there restrictions as to where boilers can be sited?
Generally boilers can be sited wherever you like. All they require is flueing to the outside and to meet all building regulations. Apart from that from country to country there can exist national restrictions which you should ask for at your local authority or installer.

Q. How are high-efficiency condensing boilers more efficient than standard efficiency boilers?
High-efficiency condensing boilers are able to capture and use much of the heat that old non-condensing boilers waste and release into the atmosphere.

Condensing boilers convert around 90% of fuel into useful heating, whereas old conventional boilers only convert around 60% and waste the rest.

Q. Is my new boiler environmentally friendly?
The boilers in Vaillant’s current range are amongst the most environmentally friendly you will find. Due to low NOX (nitrogen oxide) emission and high efficiency they pump out less C02 than older models. Plus, none of the materials used to make them contributes to the Ozone Depletion Potential and the Global Warming Potential (see below).

The Ozone Depletion Potential (ODP) is a number that refers to the amount of ozone depletion caused by a particular substance. All Vaillant boilers have an ODP rating of 0.

The Global Warming Potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. Vaillant’s boilers have an official rating of 0 in this category.

Q. Can I use copper pipe to connect the panels to the pump unit?
Yes the use of copper pipe is allowed, but it must be brazed (not soldered) or jointed using compression fittings (with brass olives).
All Vaillant Solar sets are however, supplied with stainless steel piping that requires minimal joining.

Q. Do I have to put lagging on the solar system circuit?
All pipework must be lagged with lagging that is rated for use on solar pipe work.

Q3. What is solar fluid made from?
Solar fluid is an oxygen free mix of water and (food grade) propylene glycol.

Q4. Where is the best place for the panels to be facing/placed?
The ideal orientation is south facing and at an angle of 35°- 400.


Q. Will the heat pump heat the building on a cold winter’s day?
Yes a heat pump will heat the building on a cold day. The basis for a heat pump installation should be a full heat loss calculation of the property. With this proper design, the heat pump should always be able to heat your property.

Q. Does the heat pump provide enough domestic hot water for my requirements?
Yes, this will be part of the full heat loss calculation refered to above - please also refer to http://www.vaillant.co.uk/installers/renewable-energy-1/heat_pumps-2/ground-source-heat-pump-calculator-1 for confirmation.

Q. Does the heat pump always require underfloor heating or can I use a radiator system?
geoTHERM heat pumps work best with an underfloor heating system but can be used with radiators provided these have been correctly sized for the system design.

Q. Is cooling possible with the heat pump?
When combined with a correctly designed underfloor heating system the geoTHERM exclusive heat pump is able to provide passive cooling and can reduce the temperature in the house by 3 to 4 °C.

Q. Can I use my existing domestic electrical supply?
There are geoTHERM and geoTHERM exclusive models available which are designed to run with a UK standard 230 volt, single phase electrical supply. The heat pumps have outputs of 6, 8 and 10 kW for heating and cover most domestic applications.
For larger properties 415 volts, three-phase electrical supply will be required.

Q. I want to install a heat pump but my garden is quite small. Will this matter?
With small UK sized gardens Vertical borehole loop collectors can be used. The main constraint is access for the drilling rig which has to be considered at the design stage. Much larger gardens can of course use Horizontal collector loops which may still require access for digging equipment.

Q. I have an existing property and I want to fit a heat pump. Will this be a problem?
geoTHERM heat pumps are designed to work in both new build and existing properties. It is essential that the heat loss requirements for your property is known so that the system can be designed to suit your property. Before a heat pump is considered it is important to ensure that the basic energy saving measures are in place such as draught proofing and loft insulation. The Energy Savings Trust provide information on ways to reduce energy usage and can also provide information on Government grants that may be available.

Q. Are ground source heat pumps really environmentally friendly?
A ground source heat pump is an electrical appliance, using electricity to operate the compressor and pumps. For every 1kW of electricity used to operate the heat pump, up to 4.5kW of heat energy can be provided to the house for heating and hot water. A heat pump will reduce the CO2 emissions from a domestic property by up to 35 to 40%.