Why Replacing Your Heat Meter Matters for RHI Compliance
If your biomass boiler is accredited under the Renewable Heat Incentive (RHI), keeping your system’s heat meter in good working order is essential. It’s not just about accurate readings, which are of course important as this is what your RHI payments are calculated on, it’s about making sure you continue to meet your RHI ongoing obligations and compliance requirements and avoid any interruption to your payments.
At Treco, we’ve seen an increasing number of RHI participants needing to update or replace their heat meters. Whether this is due to age, accuracy, or equipment failure, it’s an important part of maintaining your system and keeping your RHI account compliant and ensuring you don’t receive any sanctions.
Why a heat meter replacement might be needed
Heat meters are classed as measuring instruments, which means they have a defined operational life. Once that period expires, they must be recalibrated or replaced to remain compliant with RHI legislation. Typically we find the total cost to replace is cheaper than recalibration, as such this is the route people chose as they then also benefit from a new meter with warranty.
Assuming the meter was new on installation, this period is 10 years from when your RHI application was first submitted, and Ofgem keeps a record of these details.
If your meters are found to be out of date or non-compliant, your RHI payments can be suspended whilst a compliance case is raised, which ultimately results in you being fined 10% of RHI payments that are made from the 10 year mark until the meter is replaced. Currently Ofgem are only identifying out of date meters during random site audits or when amendments are made to an RHI account, they have however advised they will be reviewing all accounts during their lifetime, so it will impact each and everyone. Replacing meters before they expire helps you stay ahead of deadlines and ensures your payments continue without disruption.
Other common reasons for replacement include:
- Faulty or damaged meters
- Inaccurate readings or communication failures
- Upgrades to metering arrangements following system changes
- Moving from multiple end-user meters to a heat loss–based account (HLA or HLC)
When a heat meter needs replacing
From an RHI legislation perspective, every heat meter has a defined lifespan, which if new on install is 10 years from the RHI start date. If the meter being replaced was actually a replacement meter, then its 10 years from when the meter was installed and RHI meter amendment submitted.
After that 10-year validity period (or sooner if specified by the manufacturer), the meter must be recalibrated or replaced to stay compliant. Ofgem verifies this information using the details recorded on your RHI account and within your Independent Report on Metering Arrangements (IRMA).
During an audit or review, Ofgem may request evidence such as calibration certificates, serial numbers, or installation dates. If a meter is found to be out of date, payments can be paused or withheld until a valid meter is fitted and your RHI account has been updated.
By planning a replacement in advance, you can avoid last-minute delays and keep your RHI payments running smoothly.
Understanding HLA, HLC, and IRMA
When a heat meter is replaced, it’s often a good opportunity to review how your system is metered and reported to Ofgem. This may involve one of the following:
- Heat recorded at point of use – Heat meters are installed in all buildings and you are paid against the total eligible heat use recorded on all meters
- Heat Loss Assessment (HLA) – Used for systems accredited after 29 September 2013, where you are paid against the eligible heat generation recorded on the biomass boiler meter. A heat loss assessment is then done to work out the theoretical losses along any external pipework. This heat loss is then deducted from the total generation on the biomass meter, and RHI payments are calculated against this. If the heat loss is calculated to be <3% then they are disregarded and you can get paid for 100% of the kWh recorded on the generation meter,
- Heat Loss Calculation (HLC) – Used for systems accredited before 29 September 2013. RHI payments are calculated in the same way that they are with the HLA, though a different calculation method is used. The main difference to the HLA is that even if the losses are <3% they still get deducted before payments are calculated.
- Independent Report on Metering Arrangements (IRMA) – A technical report that may be required if calculated losses are above 3% or if there’s any ineligible heat use, such as a swimming pool.The need for an IRMA depends on the system design and insulation levels. For most post-2013 installations, if losses are under 3% and all external pipework is properly insulated, an IRMA isn’t usually required. However, Ofgem can still request one at their discretion, so it’s worth being prepared. These typically cost in the region of £1,500 to £2,500 depending on the complexity.
A lot of early systems have their RHI payments based on multiple meters that record the eligible heat used at the point of use in various building. If your account is setup like this, you will benefit from switching to a heat loss account. Switching could mean that at the 10 year mark you just have to replace the one meter that records the generation of the biomass boiler as opposed to multiple meters that record the usage in the buildings, which can save a lot of money. In switching to a heat loss account we also find people generate more RHI payments than they historically did when they were paid at point of use.
The importance of getting it right first time
When replacing a meter, it’s important to have all the necessary information gathered before work begins. This includes:
- What the biomass system heats (e.g. buildings, processes, or pools)
- Any backup or fossil fuel boilers
- The number and location of existing meters
- Details of underground and above-ground pipework
- Access to your RHI account for data verification
Collecting this information early ensures the new meter is quoted correctly, installed smoothly, and the RHI amendment is submitted promptly.
Keeping your RHI running without interruption
Replacing your heat meter isn’t just a maintenance task, it’s a key part of staying compliant with the RHI scheme. Ofgem can carry out checks at any time, and if your meters aren’t up to date, there’s a real risk that payments could be paused or withheld until the issue is resolved, following which you will be fined 10% of the RHI payments you generated whilst using a meter over 10 years old.
If your heat meter is due for replacement, or if you’re unsure when it was last changed, contact Treco. We can review your setup, confirm what’s required, and help keep your RHI account fully compliant and active. Where possible, we can carry out the work alongside a scheduled service to reduce additional site visits. We’ll also take care of updating your RHI account with the new meter details once the work is complete.
Complete our contact form below with any questions regarding a heat meter replacement and switching to a heat loss based account, or give us a call today on 01884 250790