Solar Thermal Maintenance

There are many different types of Solar Thermal installation in operation in the UK, many of which have been installed by companies that are either no longer trading or do not provide maintenance and repair services. In many cases the documentation supplied does not adequately show the system components or setup information. It is sadly also the case that many Solar Thermal installations were installed incorrectly by installers who were not completely knowledgeable about the specifics of how Solar Thermal works or the unique temperature and pressure issues. Many customers were not made aware of the real need to have systems serviced at least every year.

As a result of the above, many Solar Thermal systems are not maintained correctly and only get looked at when something goes seriously wrong. At this point, customers try to get in touch with the installation company who all too often is no longer contactable or is not interested in providing sensibly priced support.

At H2ecO, we provide full support to our own installation customers but have had so many enquiries from other people that we have put together a price list and explanatory document as to how we work.


Pricing policy

The biggest challenge with Solar thermal systems that have been installed by other companies is that we don’t know how well they have been installed or how well they have been maintained before we get to them.
The problem this creates is that it is impossible to accurately price for a job until we have seen it and done a pretty thorough survey. Even then, there may be latent faults that only come to light once we have fixed what appears to be the main problem.

As such, some companies quote a very high fixed price to give them some security that they won’t get caught out with a system with multiple faults.
At H2ecO we have decided to work on an open-book basis. As such, we have a price list of key components and an hourly rate for the work. We will always endeavor to provide the most cost effective solution to get the system working again – but it is possible that the initial estimate may not fully resolve the problem and additional components / time may need to be charged. We will not carry out work without your prior approval and we will give you our best estimate of whether it will solve any problems – but it is impossible to be correct all the time.
This is an uncomfortable position for our engineers if it happens so we want to be very clear in advance that it can happen.



Initial call from customer states that the system isn’t working and is making a lot of noise. H2ecO talks through on phone and initially it looks as if the system has lost pressure for an unknown reason. The system has not been maintained for several years. The collector is on a bungalow so no chargeable access equipment is required.

Initial estimate is that the system may have lost pressure through a failed roof mounted release valve so pricing suggests a site visit plus mileage plus a replacement valve, plus a replacement fill of thermal fluid and a pump-station clean down taking 3 hours. Approximate cost is (£150+£13.5 (30 miles) +£15+£90+£30+(2 x 42)) £382.50 (inc VAT).

If that solves the problem, it is all that will be charged.

If however, damage has been caused to the pump-station due to the lack of fluid, it will not necessarily be evident until the system is restarted. There could then be a requirement to replace the pump-station at a cost of £416.00 (inc vat) plus any additional labour required. If the old pump-station had been installed without a discharge vessel – which is now a mandatory requirement, one of those would have to be fitted at an additional cost of £50.40. If the system does not use Stainless flexi pipes the main solar thermal plumbing may have to be modified to fit the replacement pump-station as it is likely the original model is not available. This would incur costs of time and basic copper and brassware.

As you can see, it is possible for the costs to add up quite quickly if the system has multiple faults.

We have all seen the “rogue trader” TV programs where dodgy installers artificially ramp up costs and create problems but unlike a lot of domestic appliances or heating systems, Solar Thermal can have multiple points of failure which do tend to appear at the same time or close together because once one main component has a problem, the resulting very high temperatures can quickly damage other components and it simply isn’t possible to know this until the system is restarted after each fix, possibly leading to a number of sequential repairs having to be carried out.

In most cases H2ecO can diagnose the problems and estimate the total repair bill accurately in advance but we do not take any responsibility for the fact that in some cases additional faults will appear after the initially diagnosed fix and if the system is to be made fully operational, those repairs will have to be charged for.

We will not carry out work without your prior approval but it is conceivable that what initially appears to be a reasonably simple fix escalates to a point where the cost is considerable and a customer has to make a decision as to whether to continue with the repairs or not. If the decision is to stop, H2ecO will still have to charge for the work carried out to that point and for the components used. This has never happened to us and we hope it never does as the solar Thermal system will have been a substantial investment so is generally worth repairing.



The best solution is to have the system maintained properly and regularly. We recommend annually but every 2 years as a minimum. Our standard service costs £150 plus mileage and includes a visual inspection of the components, a test of the pressure relief valve (if accessible) and a test of the thermal fluid. Fluid can last for between 1 and 5 years so won’t usually need to be changed annually but will always need changing after 5 years. Fluid changes are charged per the price list if required.

We will always try to provide estimates in advance that are as accurate as possible.

We will always provide what we believe is the best value option to fix any problems with the system and will not do work that is not required.

If we attend a system that has been installed with inherent faults in design we will recommend that they should be rectified. We will carry out repairs to get it working again without fixing the inherent design faults if the customer specifically wants us to. However, if our engineers’ opinion is that to do so would leave a system unsafe, they are obliged to explain that the fault must be fixed or the system left decommissioned. At no time will an H2ecO engineer be able to restart or repressurise a system if it would be unsafe under current guidelines to do so.



Solar Thermal, PV and Heat Pump maintenance and repairs pricing

Thermal Mainenance Pricing

Latest Posts