Updated: 25/08/2026

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Woodburning/multi-fuel/gas appliances:

 

When a woodburning/multifuel or gas stove is lit for the first time visible fumes and a strong

odour may be noticeable. This is considered a normal part of the curing process when running in a brand new fire. It is not recommended to have a full sized fire straight away. To correctly run in a new stove the user should only burn a small amount of kindling for the first 3-4 fires, and gradually increase the amount of fuel after that. Some manufacturers such as Heta pre-cure their fires at their factory.

 

A seasoned log should measure no more than 20% moisture content when using a

moisture-meter. If unseasoned wood is used then this can lead to poor heat output and

blackened glass, as well as heavy deposits within the flue that could potentially build up. When using solid fuel in a multi-fuel stove, most manufacturers recommend using smokeless fuel, and do not recommend using housecoal, bituminous coal or petroleum coke. Using these fuels may invalidate the warranty of the stove and/or flue liner and cause irreparable damage.

 

Compared to log burning, smokeless/solid fuel can burn for very long periods at intensely high temperatures. This can lead to internal parts of a stove such as the grate requiring more frequent replacement, or showing signs of wear and tear. Most stoves will contain consumable materials, notably rope seals, vermiculite fire-bricks, steel baffles, cast iron grates, ceramic door glass etc. These are generally considered consumable and are not covered by any warranty.

 

Unsatisfactory weather conditions, lack of height to an existing chimney structure, lack of draught in a property, lack of maintaining the appliance (replacing rope seals/lining bricks/baffles, ash-emptying), lack of chimney sweeping can sometimes affect the performance and/or reliability of a stove/open fireplace and its ability to burn cleanly or exhaust its gasses correctly. Appliances are becoming ever more efficient in providing heat into the room, thereby reducing the amount of heat which would be consumed by the chimney. If a chimney/flue is too cold it may not be able to maintain a consistent draught until fully warmed. Houses are being increasingly sealed against draught; and this draught is essential in allowing a chimney to 'breathe'. The parameters within which an appliance and flue work are therefore becoming increasingly restricted. We reserve the right to charge for any additional products that may aid the draught of the chimney. The effective heat output of a stove will be affected by the insulation qualities of the property/room, and a recommendation will be made for a suitable heat output.

 

The user of the stove should also carry out routine maintenance every month such as checking rope seals, cleaning the throat plate/baffle, checking the condition of fire-bricks and grate. It is also recommended to leave the stove door slightly ajar during periods of non-use to help air flow through the system, which can help reduce corrosion. Any modifications made to the stove without prior approval will invalidate its warranty.

A common concern is the inner bricks may crack or craze from the heat generated. This is considered normal and they should only be replaced when they are showing signs of disintegration. Cracked fire bricks do not need to be replaced immediately and it is not an indication of a fault, as the brick may still perform as required with a crack, subject to confirmation. There is no obligation for fire bricks to be replaced free of charge regardless of age.

 

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Flexible Flue Liners & Twin-Wall Flues

 

316 or 904-grade flue liners are designed for use with approved wood/solid fuels, and must be maintained in accordance with the recommendations based on how the appliance is to be used. If solid fuel is expected to be the preferred choice of fuel it is recommended to use a 904-grade flue liner kit. Specflue 316-grade Tecnoflex flue liners carry a manufacturer's warranty of either 20 years, or the lifetime of the appliance it is installed with, whichever comes sooner.

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Burning unseasoned wood, plastic, household rubbish, unapproved fuels, or regularly combining wood and coal burning at the same time or slumbering the stove may invalidate this warranty. 904-grade liners and ICID twin-wall flues have similar warranty conditions. Please enquire for specific terms and conditions that apply to flue liners and twin-wall flues.

 

All goods supplied fall within current UK guidelines and building regulations. If external factors lead to unsatisfactory performance or additional items are required to allow suitable installation, solutions such as the provision of a taller chimney pot/flue, anti-downdraught cowl, draft-boosting fan etc will be chargeable. If a working platform such as a scaffold is needed to carry out this work, this will also be chargeable by an installer. Standard terms and conditions for flue warranties are as follows:

 

Specflue flexible 316/904 flue liners have an automatic warranty for replacement in the event

of product failure for one year from the date of installation. An extended warranty of

20 years must be registered online within 30 days of installation, which covers all

316-grade flue liners up to 12m in length, and all 904-grade liners regardless of

length.

 

This warranty will be invalidated if:

 

• The stove is repeatedly slumbered for long periods or overnight without then performing a high controlled burn for approximately 30 minutes

• Any unapproved fuel, refuse or plastic has been burnt, including housecoal

• An enclosed appliance has been operated for long periods with the door/s open

• Halogen based chemical cleaners have been used

• The appliance is located where substances containing chlorine or fluorine can be drawn into the air intake

• The chimney or liner has suffered a chimney fire

 

The chimney must be regularly inspected and professionally swept, as per the requirements according to your fuel (a qualified chimney sweep receipt must be retained), which will be a minimum of once per year, depending on fuel choice and amount of use.

 

Please note, this warranty only covers replacement of the product. It does not include any cost of re-installation or access equipment.

 

A flue/chimney with a strong draught, perhaps during periods of strong winds, may result in a stove producing a whistling noise, especially a model with tertiary/quaternary burn features. This can be reduced with a draft-stabiliser or damper, or by leaving the stove door slightly ajar when not in use. This is a result of certain air intakes on a stove which are permanently open in order for the stove to meet efficiency criteria such as Defra/Ecodesign approval.

 

Natural Stone Fireplaces:

 

Materials such as limestone, marble, granite, slate, sandstone are not manufactured or man made but are natural materials, and therefore are likely to have markings that are not 100% uniformed or consistent. Each stone fireplace is unique, so should not be compared too closely with showroom displays or other stone sample pieces. Because of the characteristics of natural stone we check each piece as it is unpacked for damage, as well as unsightly defects that may warrant a replacement, before it is installed. However, if the customer is not comfortable with the characteristics of natural stone then we would recommend considering an alternative material, e.g. conglomerate/micro-marble, if suitable for use with the intended appliance.

 

Markings that do not warrant replacement fireplaces include small holes (vents), hairline veins (not to be confused with a crack), fossils and other individual light or dark marks that are generally smaller than a 5 pence coin. “Whisps” (fossilised fern leaves) are also possible. These are considered characteristics of the stone. Due to the way the most stone fireplaces are packaged we do not unpack the fireplace until it is delivered to the customer to avoid any chance of damage.

 

All acids attack and corrode limestone. Take care, therefore, to prevent materials containing acid such as wine, fruit-juice, fizzy drinks, vinegar, lemon-juice or acid-containing cleaning materials from coming into contact with the stone and thereby damaging the surface.

 

Gas and Electric Fires:

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Gas fires require annual servicing by a qualified Gas Safe engineer, regardless of how much it has been used. If this is not routinely carried out the fire may develop problems and in some cases may void the manufacturer's warranty. Many gas fire models rely on batteries to power certain components - these are consumable items and not covered by any manufacturer's warranty regardless of age, and if they run flat the fire will not operate properly. If a user is

experiencing problems with a battery-powered gas fire, we recommend changing all batteries in the handset, receiver unit or control unit with a high quality brand such as Energizer before contacting Henry Isaac Fireplaces or a Gas Safe engineer. If a visit to a property is required  to inspect a fire to diagnose a problem, Henry Isaac Fireplaces reserve the right to make a reasonable and fair charge if a problem is due to flat batteries to cover the cost of the batteries and travel time.

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It is recommended to make a note of the model/serial number for a product should there be the need to refer to it in the future. Some electric fires may require registration with the manufacturer to activate the warranty, e.g. Solution, Celsi. This can be completed on the manufacturer's website. The effective heat output of a gas/electric fire will be affected by the insulation qualities of the property/room.

 

Deliveries and Orders

 

Once an order is placed, Henry Isaac Fireplaces will take delivery from the suppliers and store the complete order until delivery is required. Installation of the orders is arranged and managed specifically by the installer (not Henry Isaac Fireplaces), and it is recommended that any dates for installation should be discussed directly between the customer and installer. Deliveries to customer/site addresses will not be carried out unexpectedly, they will be confirmed in advance to ensure suitability. Regarding deliveries which involve very large/heavy items it is the responsibility of the customer to ensure suitable access is available to allow delivery into the actual room the appliance is to be installed. This is especially relevant for long “media wall” electric fires which can be upwards of 2m in length. If safe and suitable access is not available the delivery may have to be left at the closest and most secure place such as a garage. A charge may be applied for deliveries depending on the distances and products involved. For heavy items it is requested that suitable parking and access is maintained to allow safe deliveries without inconveniencing pedestrians/neighbours. Some items may be unpackaged to allow easier manoeuvrability, any surplus packaging will be left with the customer for recycling/disposal.

 

All supplied goods remain the property of Henry Isaac Fireplaces Ltd until paid in full. A deposit amount will be discussed at our discretion based on the value of the order. The balance payment for the order is due when delivery to site has been completed. If overdue amounts have to be recovered, the customer will pay in full any expenses incurred in the process. If a customer cancels an order after the goods are in stock this may result in a reasonable charge to cover any manufacturer's restocking fees. This could be in the region of 10-20% depending on the manufacturers and products involved. If a customer decides to cancel an order any deposit paid will not be refundable.

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If it becomes clear during installation that additional items are required, these items will be supplied at a fair cost. This may be relevant if for example during the quotation process it was not possible to confirm that certain items were required, such as an offset flue pipe or a replacement chimney pot.

 

After delivery/installation, if a customer decides to not use individual items and they are returned Henry Isaac Fireplaces reserve the right to charge a 20% restocking fee. If any items are returned in a state that makes them unsuitable for returning to the manufacturer, such as without any packaging or with damage, the customer may be liable for full payment for these items.