© HETAS 2015 H008
HTU13Pellet stove Sizing, Selection, Installation, Commissioning &
Decommissioning
© HETAS 2015 H008
Introduction
• The learning outcomes for HETAS Unit HTU13C - Dry Pellet
Stove Appliance Sizing, Selection, Installation, Commissioning &
Decommissioning are:
• Know dry pellet stove types and operating principles.
• Be able to select a dry pellet stove appliance.
• Know dry solid fuel appliances installation requirements.
• Know the commissioning and handover requirements of dry pellet stove appliances.
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• The learning outcomes for HETAS Unit HTU13C - Dry Pellet
Stove Appliance Sizing, Selection, Installation, Commissioning &
Decommissioning are:
• Be able to inspect an installed dry pellet stove appliance to determine if commissioning can go ahead.
• Know the service and maintenance requirements for dry pellet stove appliances.
• Know the fault diagnosis and rectification procedures for dry pellet stove appliances.
Introduction
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Pellet Stoves
• The appliances discussed in this manual are compliant with EN 14785 and a minimum efficiency of 65% part load - 70% nominal load.
Reference - 'Domestic Building
Services Compliance Guide 2010',
Table 18.
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Renewable Heat Incentive & Microgeneration Certification Scheme
Requirements
• Pellet stoves with boilers are eligible for RHI payments where the appliance and the installer is MCS approved in accordance with ‘Microgeneration Installation Standard’ MIS 3004.
• ‘Requirements for MCS Contractors undertaking the
supply, design installation, set to work, commissioning and
handover of solid fuel heating systems'
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Microgeneration Certification Scheme Registration
• Successful completion of this course together with a wet competency such as is awarded on completion of the HETAS H004 Wet Appliance Installer course may provide a pathway for limited scope MCS certification. Installers wishing to pursue MCS registration in mind of the Renewable Heat Incentive may seek further information, guidance and MCS registration through HETAS.
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Why Choose a Pellet Stove?
• High efficiency. • Highly controllabe.• Automated - little consumer
interaction required.• Convenience of fuel availability.• Low ash content.• No need to open combustion
chamber during normal operation therefore spillage flue gases is not an issue.
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Why Choose a Pellet Stove?
• Many are exempt appliances and as such are suitable for installation in Smoke Control Areas when using specified fuel.
• Many are freestanding and as such do not require a recess or builder's opening for their installation.
• Pellet appliances include several modern and stylish designs.
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Certified Pellet Fuel
• Pellet stove manufacturers will specify the appropriate fuel to be burned in their appliance. It is likely they will refer to fuel standards such as EN 14961-2, or ISO 17225-2, or ENplus. These standards specify the physical and property characteristics of pellet fuel to ensure the pellet appliance operates efficiently and effectively.
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Wood Pellet Schemes - ENplus
• Fuel quality is decisive for the optimal operation of a pellet stove. For use in private households many appliance instructions will recommend using ENplus A1 certified pellets.
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Wood Pellet Schemes – Woodsure Plus
• In conjunction with Woodsure HETAS certify producers that meet high standards in the production of firewood, briquettes, wood chip and pellets. Refer to Part 3 of The Official Guide to HETAS Approved Products & Services for a list of approved biomass producers, including pellet suppliers.
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Wood Pellet Schemes
• ENplus and Woodsure Plus certified by HETAS pellets will carry one or both of the previous logos on their packaging. You should advise your customers to look out for them.
• HETAS produce consumer advice leaflets on fuel quality, operating a stove and CO awareness amongst others. These are free to download from the HETAS website or available in printed form for registrants in the HETAS online shop.
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Pellet Storage
When discussing the installation of a pellet-fuelled appliance with the customer consideration should be given to the following:• the economical delivery of pellets
(blown/bagged) • for blown delivery a dedicated area for a fuel
store will be required.• access for potentially large delivery vehicles
to the property • dry secure storage of fuel • the consumer’s ability to convey bagged
pellets from storage to the appliance. http://www.pelletcouncil.org.uk/news/new-video-doing-wood-pellets-right
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Pellet Storage
• Large separate hoppers and silos are discussed in the manual for Unit HTU01K.
• Most dry pellet stoves as covered in this unit will feature an inbuilt storage hopper typically with capacity to hold 15-50kg of pellet fuel.
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Pellet Storage
• For freestanding stoves loading of the pellet hopper is relatively straightforward and involves lifting the hopper cover and pouring in the pellets either, directly from the bag (Figure 9) or using a fuel shovel.
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Dry Pellet Fuel Appliance Selection
HETAS approved dry pellet stove appliances are listed in The Official Guide to HETAS Approved Products & Services under the following category:
• Type E4 – Wood Pellet Stoves.
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Dry Pellet Fuel Appliance Selection
The selection of any dry solid fuel appliance including pellet-fired appliances should be made after taking into account: • The customer’s stated
preferences/requirements• Regulatory requirements • Room heat requirements• Appliance manufacturer’s
requirements including flue specification
• Access for both maintenance and fuel delivery
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Dry Pellet Stove Types & Operating Principles
• Dry pellet stove are available in a range of styles and types that includes inset and freestanding options (see Figures 6 & 7.)
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Figure 8 (p9)
1.Pellet burner bowl/crucible2.Ash pan3.Combustion chamber4.Flame temperature sensor5.Safety temperature limiter6.Pellet hopper7.Control panel8.Pellet feed system9.Remote sensor (if fitted)10.Modem (if fitted)11.Automatic ignition system12.Exhaust gases13.Air Intake14.Combustion air fan
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Figure 10 (p10) Inset with frontal feed tray
1.Pellet burner bowl / crucible
2.Outlet from pellet feed system
3.Frontal pellet feeding tray
4.Pellet hopper
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Pellet Stove Components
• Combustion Chamber• Pellet Feed System• Pellet Feed System - Top feed• Pellet Feed System – Bottom Feed
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• Combustion Air Fan• Automatic Ignition System• Control Panel
Pellet Stove Components
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Figure 12
1. Pellet hopper2. Screw feed3. Air lock (back
burn protection)
4. Discharge chute
5. Igniter6. Forced air
induction7. Ash collection8. Fire grate9. Secondary
combustion chamber
10. Air wash
(courtesy Euroheat)
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Other Features
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• Air wash glass cleaning system• Ducted air distribution • Direct Air Supply • Fan assisted convective heat• Flue gas outlet safety device
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Other Features
???
• Overheat protection • Low temperature protection • Automatic tipping grate.• Ash compactor• Safety features on doors .i.e. microswitch
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Power Failure
• In the event of power failure the appliance will shut down as no fuel can be delivered and fan will not be operational for combustion to take place
• Appliance restart after a power failure is normally automatic.
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Pellet Stove Installation
Pre-installation Checks
• Electrical Work - Much electrical work is notifiable and as such anyone carrying out electrical work in relation to the installation should be deemed competent under Part P of the Building Regulations.
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Pellet Stove Installation
Pre-installation Checks• Once the appliance is selected,
HETAS recommends that pre-installation checks should be carried out in order to determine if the proposed installation will be compliant with relevant regulatory requirements and the appliance manufacturer’s installation requirements. As a minimum the pre-installation checks listed in Table 2 are recommended.
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Pellet Stove Installation
• The appliance must be installed in accordance with the Building Regulation requirements and with due regard to the manufacturer’s instructions (Refer to the HETAS manual for Unit HTU03K). In this section we examine a cross-section of installation requirements that may be applicable.
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Connection of the Appliance to the Chimney
• Many pellet stoves have a low level rear flue outlet with a diameter in the range 80-100mm. The appliance manufacturer may specify that the appliance is fitted with a standpipe and connecting flue pipe (see Figure 13).
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Commissioning & Handover
• Commissioning is carried out when the installation is practically and technically complete and will include the whole installation. It is the final and important stage prior to handover of the installation to the homeowner or end user.
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Commissioning & Handover
Within this section we consider:• The documentation required for
commissioning to proceed.• Pre-commissioning check
requirements.• Typical commissioning requirements• Typical handover requirements.• Equipment required for
commissioningRefer to p2 of the MCS Handover document for eligible installations.
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Documentation Required for Commissioning to Proceed
The typical documentation that needs to be available to enable commissioning work to proceed is:• The appliance manufacturer’s
commissioning instructions.• A blank commissioning record and
checklist (unless included in the appliance manufacturer’s commissioning instructions). An example basic commissioning checklist is provided in the HETAS training manual for Unit HTU03K.
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Pre-Commissioning Check Requirements
• HETAS recommends that a number of checks are carried out prior to commissioning
• This is particularly important if the installation has been undertaken by other personnel.
• Table 3 identifies a number of typical
pre-commissioning check requirements.
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Commissioning Requirements
• The commissioning of a dry pellet stove must be undertaken in accordance with manufacturer’s instructions and relevant regulatory requirements.
• Including completion of Manufacturers commissioning document.
• Table 4 details the typical commissioning requirements.
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Commissioning Requirements
Information required for commissioning to proceed:• Manufacturer’s data and instructions• Access to controls to check preset
values• Error codes and their meanings
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Commissioning Requirements
• In the event that commissioning cannot be correctly completed, reference should be made to the HETAS unsafe situations procedure and where relevant the procedure should be followed.
• Refer to the HETAS manual for Unit HTU03K for guidance.
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Commissioning Requirements
• Where required by the Building Regulations, the relevant building control authority must be notified of the commissioning of a solid fuel appliance. This can be completed by a Competent Person registered with HETAS.
• The HETAS manual for Unit HTU03K provides guidance on Building Regulations notification requirements and available options and procedures for providing notification.
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Installation Handover
The handover of a dry solid fuel appliance installation will typically involve discussion and provision of written information and a demonstration to the customer or the customer’s representative to include, as a minimum, the following:• Explanation of each item of
documentation provided (user instructions, commissioning certificate, warranty document etc.)
• Details of suitable pellet fuel including Enplus bagged delivery
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Installation Handover
• Demonstration of how to load the appliance with pellet fuel
• Demonstration of appliance light-up and shut-down procedures
• Demonstration of how to set/adjust appliance controls
• Details of cleaning/maintenance that needs to be undertaken by the appliance user
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Installation Handover
• Details of the required frequency for sweeping of the chimney (Refer to the HETAS manual for Unit HTU05C for guidance).
• Details of potential error codes, their meaning and actions to be taken
• Advice on the importance of appliance lockout and recognising the reasons before attempts to reignite or overriding error messages
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Installation Handover
• Details of the appliance maintenance that needs to be undertaken by a competent person.
• What to do in the event of an emergency or perceived emergency (e.g. activation of the CO alarm* or a chimney fire**).
*Refer to the HETAS manual for Unit HTU01K for guidance** Refer to the HETAS Guide (Part 4) for guidance
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The Importance of Notice Plates
• It is a legal requirement for you to affix a notice plate when you complete an installation. (J5)
• Failure to do this makes it a NON-COMPLIANT
INSTALLATION!
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CO Detectors/ Alarms
• It is also a legal requirement for you to install a CO Detector/Alarm.
IN THE SAME ROOM AS THE APPLIANCE (refer to Unit 1, page 37)
Failure to do this….. ….you guessed it!
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Installation Handover
• In addition, installers may wish to offer an annual service contract as part of the handover process to ensure ongoing appliance safety and efficiency. With this in mind HETAS produce a variety of supporting documents for its registrants including the below, where a copy can be left with the homeowner, servicing installer, and tenant if applicable.
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Dry Pellet Stove Service & Maintenance
Main factors that have contributed to serious incidents are:• Blocked flue• Leaking flue/chimney structure• Lack of or insufficient permanent
ventilation• Lack of appliance cleaning and
maintenance including blocked flue ways within the appliance
• Poor quality fuel• Poor installation practice
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Dry Pellet Stove Service & Maintenance
It is therefore essential that routine servicing of any dry solid fuel appliance includes inspection and/or testing to check the:• Condition of the chimney
structure/flue• Permanent ventilation to the
appliance• Overall installation of appliance in
relation to manufacturer’s instructions
• Overall installation of appliance in relation to applicable regulatory requirements
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Dry Pellet Stove Service & Maintenance
• Evaluation of use and maintenance carried out by the customer
• Routine service and maintenance of the appliance must always be carried out by a competent person in accordance with the appliance manufacturer’s requirements.
• Further guidance on page 23 HTU13
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Dry Pellet Stove Service & Maintenance
• The service intervals should be as stated by the appliance manufacturer.
• Where no service interval is given by the appliance manufacturer HETAS recommends that routine servicing of the appliance / Flue/ Chimney is undertaken at least once a year.
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Fault Diagnosis & Rectification
As with routine service and maintenance, fault diagnosis and rectification of the appliance must
always be carried out by a competent person in accordance with the
appliance manufacturer’s instructions.
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The typical requirements for routine service and maintenance of pellet stove are:
Group Activity • Compile a list of the typical
requirements for servicing and maintenance.
• 15 minute activity without the use of reference material.
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Fault Diagnosis & Rectification
The diagnosis process may require some or all of the following activities to be undertaken:• inspecting and testing of the chimney/flue
system provision and operation• checking the permanent air supply
provision • inspection/cleaning/testing of appliance
components • Review of error codes and their meanings
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Dry Pellet Stove Decommissioning (p30)
Decommissioning of a dry pellet appliance may be required:• To enable servicing and maintenance
work (temporary decommissioning); or
• Because the appliance has reached the end of its useful life, become obsolete or is inefficient; or
• Beyond economic repair (permanent decommissioning).
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Safe Electrical Isolation
• Prior to the commencement of routine servicing and maintenance or fault diagnosis and rectification work on a solid fuel appliance there is a need to safely isolate the appliance from the electricity supply.
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Examples of where full re-commissioning is required include, but are not limited to:• Repairs to the appliance chimney or
flue including the replacement of, or alteration to, any connecting flue pipe;
• Alterations to the appliance permanent air supply;
• Repairs following the activation of a CO alarm;
• Repairs following a chimney fire. • Persistent error codes