Biomass Boiler Maintenance

March 7, 2017 1:45 pm

Cleaning and biomass boiler maintenance.

Maintenance of a biomass boiler differs from other fossil fuel boilers because of the ash they produce in the combustion process must be disposed of.

A helpful way of finding out when your biomass boiler needs cleaning is to note increases in your fuel consumption. The main reason there is an increase in fuel consumption it due to the ash blocking the usually open airways of the heat exchanger & reducing the transition of heat into the heating system.

Depending on the quality of the fuel used, wood combustion can produce between 0.5-1.5% of their weight in ash. The ash is held in an ash pan located beneath the grate. This collected ash must be removed manually at regular intervals necessary in-between services, we normally recommend empty after every tonne of fuel used. The regularity of these intervals will vary depending upon how often the boiler is used for heating. Automatic de-ash systems can be used to empty the ash into an ash bin, thus lessening the work load required, but the ash bin itself will still need to be emptied from time to time.

Adding to the environmental friendliness of biomass boilers because the collected ash can be used as a fertiliser & many of our customers find the burned ash is great to use around the garden.

The flue and chimney like any solid fuel appliance, must be swept at least once every year.

Please see your user guide for more information on the maintenance required for your boiler

Biomass boiler maintenance

Disposing of boiler ash

The major by-product of biomass fuel burning is the ash that is creates. The ash created by biomass boilers and their fuel is potash. Potash is considered valuable by farmers as a top dressing and can also be used by horticulturalists as a component of their compost. You should be able to find someone who would be interested in using the biomass boiler ash as a fertiliser if you are not interested in using it yourself.

Disposing of ash in this way is highly environmentally friendly because the nutrients from the ash are fed back into the earth & could possibly regenerate the wood that was collected to form the fuel in the first place. This is especially important as the popularity of biomass fuels increases and the need for wood regeneration grows.

If you cannot dispose of your biomass boiler ash as a fertiliser or if the ash produced is only of a very small amount, you can dispose of it as landfill waste.

In cases where a large boiler is fitted with flue gas cleaning equipment and the fly ash is collected separately, the ash may have to be classed as special waste due to concentration of any heavy metal in the fly ash exceeding a threshold value. At the moment there is not any regulation in the UK to stipulate that bottom ash and fly ash must be separated.

We recommend regular maintenance checks.

Whilst manufacturers will supply basic notes on the cleaning and servicing of your biomass boiler regular checks by a qualified service engineer are necessary for a more thorough service.

Service engineers will be able to spot any parts of the boiler not operating properly & replace them to keep the boiler running at the greatest possible efficiency & minimise down time. Our service engineers will also oil the mechanical components of the boiler where necessary to keep the boiler running smoothly.

A service engineer should check the boiler at least every 12 months, it is generally more cost effective to schedule regular checks rather than to hire an engineer to carry out repairs which could have been avoided. Make sure to hire a qualified quality assured engineer to check your boiler.

Check out the photos below of a before & after from one of our recent biomass boiler services. As you can see if this boiler was left any longer it could have a serious effect on it’s function & efficiency.

What to expect on an annual inspection.

Upon every visit we kindly ask the boiler be switched off 24 hours prior to the visit. Our visit will include:

  • Internals within the heat exchanger is thoroughly inspected and cleaned. All airway ports, primary and secondary are cleared of carbon build up.
  • Boiler and bunker feed screws are examined and cleaned where necessary.
  • Geared motor units, seals, and bearings checked and greased where necessary.
  • Inspection of anti-burn back protection/safety equipment.
  • Inspection of the automatic ignition system.
  • Electrical inspection of boiler connections and control panel.

Upon completion, a service report will be issued and notification of any remedial work required.

Call outs Breakdowns can usually be attended by our experienced diagnostic engineers within 48 hours. Priority call outs are usually attended within 24 hours. All workmanship is guaranteed for 10 years.

Service numbers: Call The energy smart group on 01709 702737

For emergency call out please call Matt on 07792412854

Biomass ash and cleaning

More reasons to have your biomass boiler serviced.

Regular servicing will reduce the risk of breakdown, improve quality of emissions, maintain combustion efficiencies and help prolong the life of your boiler as well as save on fuel.

Plus in order to qualify for the Renewable Heat Incentive and comply with the warranty conditions your boiler must be serviced in accordance with manufacturer’s recommendations.

We know that each biomass installation is unique so our service and support options allow you to build up a service package to suit you, taking into account the boiler operation and fuel type.

Our biomass service packages include:

Two annual visits (including one full service and one combustion check)

An annual biomass boiler service visit costs £300.00 plus vat

Any further bolt-on options can be added as required ensuring you only pay for what you need.

If you run your boiler all year round a high usage contract may be applicable to cover the hours your boiler will be operational per annum.

Our standard service in more detail.

  • Inspect and clean heat exchanger (clean on non-HVA systems)
  • Inspect boiler access door seals and replace as necessary
  • Inspect hearth / grate elements
  • Inspect boiler exhaust system
  • Inspect mechanical seals
  • Inspect refractory linings
  • Inspect ignition device (where applicable)
  • Lubricate and adjust all running gear (drive chains and bearings)
  • Clean heat exchanger
  • Check all control system power terminal integrity
  • Check all panel hardware integrity
  • Ensure safety systems are fully operational
  • Test, run and check operation of all boiler systems
  • Record and report all findings, settings and any future replacement requirements
  • Flue Cleaning is available – ( after a quote has been issued and agreed ) *
  • Fuel storage and associated auger cleaning providing the fuel is at level to be able to carry out works


A combustion check includes

  • Investigate fault log
  • Carry out a combustion check
  • Test, run and check operation of all boiler systems


Our bolt-on options can be added to your service contract and quoted as required these include:

  • Remote monitoring bespoke packages can be
  • Additional commissioning visits
  • Monthly maintenance checks relieving the property owner of the need to employ an engineer
  • Annual silo maintenance
  • Trough filling elevator system maintenance
  • Heat meter checks
  • Flue cleaning
  • Performance Optimization

For more detail of our bolt-on options or to enquire about bespoke support for your plant room please contact a member of our team.

Complete biomass boiler maintenance and service history.

Following each service visit our engineers will complete a full maintenance report detailing any observations, repairs or adjustments made – ensuring you can build up a full service record for your system.

The service frequency for your boiler is detailed in the operations and maintenance manual supplied with the boiler.

Should the boiler be running more than the estimated hours, the boiler installer will advise of any amendments required to the agreed service plan.

Please remember that before any planned service work can be carried out it is important that the boiler is allowed to cool down for a period of 24 hours to ensure a safe working environment.