Solar Water Heating - FAQs
Based on many years experience we have compiled a comprehensive list of questions that we often get asked. If you cannot
find an answer to your question please don't hesitate to contact us by
phone or email.
Q. Should I install evacuated tubes or a flat plate collector?
We are happy to install either. Evacuated tubes are more
efficient than flat plate collectors but this can be compensated by
increasing the size of the flat plate collector. Output vs Cost is
better for flat plate collector installations.
Q. How much does a solar thermal installation cost?
This depends on your exact requirement but typically between £4000 and £6000 inc VAT.
Q. Are there grants available for solar thermal installations?
IES are approved MCS installers so you could be eligible for a
grant from your local council or the government. The Renewable Heat Premium Payment (RHPP) is currently available which provides homeowners with a grant of £600.
Q. Will I be eligible for the new Renewable Heat Incentive (RHI)?
The RHI promises to pay 17.3p/kWh for every kWh that the solar
thermal system is predicted to output (proposed for Spring 2014). IES
is an approved MCS installer so our installations are eligible.
Q. How much energy will the solar panels output?
Our solar thermal installations typically output between 1000 and 2500 kWh.
Q. I’ve heard that grants are difficult to get, is this true?
No, this is a rumour spread by unapproved installers. Any
local council grants are usually simple to apply for you should contact
your local council to check availability and the application process.
Q. Can I obtain the RHI and grants through any installer?
No, most installers are not approved by the Government’s
microgeneration scheme so cannot offer you genuine incentives from the Government. Be wary of grants that the supplier can arrange for you,
this is usually simply a sales discount.
To be sure look for the MCS approved installer logo, see 'Our Approvals' page
Q. What is the payback for a solar thermal installation?
Our systems typically payback around 2-3 times over 25 years
of use. This is based on a predicted fuel inflation from Ernst & Young of 12.9% per annum and ignores the pending RHI payment scheme which will massively improve this calculation.
Q. Do I need to replace my hot water cylinder?
Most people do not have a spare heating coil in their cylinder
so we usually need to replace the cylinder. Be wary of systems that
utilise your existing cylinder as these solutions will compromise the
output of the system massively.
Q. Can I have solar panels if I have a combi boiler?
Yes, we have a specially designed system that works very well
with most combi boilers. It requires the installation of a storage
cylinder and our combi boiler ‘Intelligent’ control package.
Q. Do you offer solar thermal DIY kits?
Usually not, solar panels are relatively simple in operation
but it is important that they are installed properly if they are to
have a long and trouble free life. We frequently see DIY and non
specialist plumber installations that do not take into account the very
high temperatures our solar panels achieve. Problems range from
melting pipe clips and insulation to soldered joints that develop leaks
after a few years of use.
Also DIY installations will not be eligible for government
incentives and RHI scheme.
Q. Does my roof need to face south?
South facing roofs at a 30 degree angle offer the best annual
output. However, east or west facing roofs can function very well as
the available solar radiation only reduces by about 20% in these
orientations. We can increase the size of the panels to compensate for
Q. Are your panels approved?
We only use the very highest quality of materials. The
panels we use meet all the required standards including Solar Keymark
and MCS approval for Government incentives.
Q. Do you work with domestic or commercial clients?
We work with both domestic and commercial clients.
Commercial systems are usually more involved than domestic applications
so you should contact us to discuss your requirements.
Q. How much space do I need on my roof for a solar thermal installation?
Typical installations have panels sizes occupying 4.6 or 6.9m2 of roof area.
Q. Whose panels and tubes do you use?
Typically we offer high quality German manufactured panels and tubes from Schueco and Viessmann.
Q. What guarantees will I receive?
We guarantee our solar thermal collectors for 10 years. Most other
components and labour is usually guaranteed for 2-5 years. Be wary of
companies offering excessive guarantees on solar thermal products.
These usually come from cheap unknown manufacturers who have nothing to
loose by offering long guarantees, also check the small print for
exactly what is covered. These guarantees do not cover the main
components that may fail such as a circulation pump.
Q. Do I need planning permission?
Our roof mounted systems do not need planning permission unless the property is listed or in a conservation area.
Q. Will my roof be strong enough?
Most roofs are strong enough to take a solar installation without any reinforcement. IES can advise you on this.
Q. Do your prices include for Scaffolding?
Surprisingly, many solar thermal installers do not include for installing the necessary scaffold at your property. We include for scaffolding installation in all our prices unless there is a specific reason for us not to do so.
Q. How are the panels fixed to the roof?
For a standard roof we use rigid stainless steel brackets that
are fixed directly to your roof rafters. The brackets hook out from
underneath your existing tiles. We do not drill tiles/slates or use mastic/silicone to weather proof your roof. These techniques do not have a long life span.
Q. How long will the installation take?
Installation normally takes 2 days.
Q. How much do Solar Thermal collectors weigh?
Our systems weigh about 19kg per square metre.
Q. Are the collectors fragile?
No, the solar collectors we use are designed to be very
robust. We use toughened glass that will resist hail stones and other
Q. How hot will the solar heated water get?
The panels can routinely exceed 100 degrees C. Given the
high temperatures it is important that pipe clips, insulation/lagging
and pipe joints can withstand up to 150 degree heat.
Q. Do I need permission from Building Control to install solar panels?
Building Control have some specific criteria in determining
whether your need to submit a buildings notice. We will discuss this
with them and you on a case by case basis. A buildings notice is usually not required but given that different building control offices deal with
these products in different ways you should contact your local office to
confirm. Be wary of installers who are not aware of how an installation
will involve building control.
Q. Can I power the circulation pump with a solar PhotoVoltaic (PV) panel?
Some systems use a small PV panel to power the circulation
pump. These systems tend to be fairly low in cost to install (as they
do not require an electrician) but they are less efficient than our
system which utilises a mains powered pump. Our panels can provide heat
to the water cylinder even in low light conditions, PV powered pumps
do not operate properly in low light conditions.
Q. Can I heat my house and my hot water with solar?
Most houses in the UK need their heat during the winter when
solar radiation is at a minimum. This means that to heat your
property you need very large collector areas to make a worthwhile
contribution to your heating. At the moment this solution is not cost
effective for the UK climate.
Q. Can I heat my swimming pool with solar panels?
Yes, indoor and outdoor swimming pools can be heated with
solar panels. This can be a very effective way of reducing the heating
and Co2 costs associated with swimming pools.
Q. What happens to the panels when I go on holiday?
You can leave the system switched on and it will continue to
heat your cylinder while you area away. Unlike some, our system will
not be damaged by periods of minimal use.
Q. What is the output of a solar thermal panel in terms of kWh?
Typical outputs from a domestic solar water heating system are in the range of 1000 – 2500kWh per year.
Please note that these answers are designed to be appropriate for typical installations. The exact specification for your system will be detailed in your personal proposal.