MORSO S11-90 (01) PDF Document

The MORSO S11-90 stove weighs from 70 to 110 kg (150 to 240 pounds). To avoid any damage during unpacking and installation, it is recommended that two people perform the task.

It is wise to consult your local chimney sweep before installing the MORSO S11-90 stove. In any event, the chimney sweep must be notified once the wood-burning stove has been installed. The chimney sweep will inspect the installation and schedule sweeping intervals with you. If your chimney has not been used for some time, it should be inspected for cracks, bird nests, etc., before it is used.

Distance requirements apply only if the MORSO S11-90 stove is placed near flammable materials. The minimum distances are as follows:

The distance to flammable material in front of the stove is 800 mm.

The floor: If the MORSO S11-90 stove is installed on a flammable floor, national and local regulations must be observed regarding the size of the non-flammable underlying surface that must cover the floor beneath the stove. The underlying surface must be able to bear the weight of the stove and, if applicable, the steel chimney.

Distance to furniture: We recommend that the MORSO S11-90 stove be installed 800 mm from furniture, but consideration should also be given to whether furniture, etc., will dry out as a result of its proximity to the stove. The distance to flammable material in front of the stove is also 800 mm.

Distance from masonry: We recommend that the stove be installed at least 10-15 cm from masonry in order to allow heat to circulate and to facilitate cleaning of the inside and outside of the stove.

An efficient, modern stove like the MORSO S11-90 places great demands on the chimney. You should have a chimney sweep check its condition.

Aperture: The aperture of the chimney must comply with national and local regulations. In general, the aperture area should measure at least 175 cm² (150 mm diameter). An overly large aperture will require too much energy to heat the chimney sufficiently. If you have a brick chimney with a large aperture, we recommend installing an insulating chimney liner of the proper diameter.

Height: A chimney must be tall enough to provide a good draught. As a general rule, there will be a satisfactory draught if the chimney extends 4 metres above the stove and at least 80 cm above the spine of the roof. If the chimney is located along the side of the house, the top should never be lower than the spine of the roof or the highest point on the roof.

Connection Restrictions: The MORSO S11-90 must never be connected to a chimney to which a gas-burning stove is already connected. If local regulations permit, it may be connected to a chimney already serving another fireplace (like an oil-burning stove).

Mounting the flue collar pointing upwards (Top Exit):

The MORSO S11-90 stove comes prepared for a top exit flue collar. Take the baffle plates out to facilitate installation. Fasten the enclosed cast-iron flue collar to the top of the stove with the included screws. The ball stop, a 160 mm long rod, should be fitted when installing the chimney to prevent the chimney sweep from damaging the baffle plates.

Mounting the flue collar to the rear (Rear Exit):

1. Take the baffle plates out of the stove to facilitate installation.

2. Remove the knock-out cover from the rear heat shield with firm taps of a hammer next to the small connecting “bridges”.

3. Remove the cover from the rear convector plate using the same method.

4. Unscrew the round cover from the back panel of the stove and reinstall it in the hole in the top panel.

5. Fasten the enclosed cast-iron flue collar to the back of the stove with the included screws. The ball stop is not used for a rear flue collar installation.

6. Finally, place the enclosed cover plate in the top panel to cover the flue exit hole.

Before lighting the stove, always ensure the baffles are correctly assembled.

Connecting to a brick chimney:

Securely brick a flue bushing into the wall and insert the flue pipe into it. The pipe must not extend into the actual chimney opening, but only to the inside of the chimney aperture. The joints between the stove/pipe and pipe/wall bushing must be sealed with glass tape. If the flue pipe transitions from horizontal to vertical, it is a good idea to install it with a gentle bend to avoid any loss of draught.

Connecting to a steel chimney:

If your installation involves taking the chimney straight up and through the ceiling, you must comply with all relevant building regulations and manufacturer instructions concerning clearances to combustible materials. The joint between the stove flue collar and the stovepipe must be sealed using the provided glass fibre rope. It is important that the insulated flue system is properly supported at both ceiling and roof level. The MORSO S11-90 stove must not bear the weight of the chimney system. Excessive weight can cause damage not covered by the guarantee.

If smoke comes out of the MORSO S11-90 stove when the fire door is opened, it is due to poor draught. This stove requires at least 12 PA of chimney draught. The draught is the result of the temperature difference between the hot chimney and the cooler outside air.

The draught will be reduced when:

• The temperature difference is too low (e.g., poorly insulated chimney). If the chimney is cold, it may help to light a rolled-up newspaper in the cleaning door.

• The outside temperature is too high (e.g., during summer).

• There is no wind.

• The chimney is not tall enough, sitting in the lee of the roof or tall trees.

• Air is entering the chimney in undesired places (e.g., through cracked joints).

• Unsealed, unused fireplaces are connected to the chimney.

• The flue pipe and chimney are clogged with soot due to inadequate cleaning.

• The house is too tightly sealed, requiring a fresh air supply.

A good draught is achieved when:

• There is a big temperature difference between the chimney and the outside.

• The weather is clear and there is a good wind.

• The chimney is of the proper height (i.e., minimum 4 metres above the stove) and clear of the spine of the roof.

The MORSO S11-90 stove has three air supplies, regulated with the handle beneath the door. When the handle is in the centre position, the air supply for combustion is closed.

• Firing with wood: Only the secondary air supply is used. The preheated secondary air is supplied when the handle is turned towards the right.
• Firing with solid fuel: Primary air, used only for approved manufactured smokeless fuel, is supplied when the handle is turned towards the left.

A third, continuous preheated air supply cannot be regulated. It feeds air to the combustion right above the fire to ensure all gases from the wood are burned.

Note: BITUMINOUS HOUSE COAL SHOULD NEVER BE USED IN YOUR STOVE.

You should not fire your MORSO S11-90 with wet or unseasoned wood. Wood should be stored under a roof for at least 1 year (preferably 2 years) with free access to wind. It should be chopped as soon as possible after felling to dry quickly. Use wood with a moisture content of less than 20%.

Never use driftwood (high salt content), impregnated or painted wood, or chipboard, as they emit damaging or poisonous smoke and fumes.

Fuel Size and Quantity:

• Pieces of wood with a diameter exceeding 10 cm should always be chopped.

• The maximum length of fuel is 30 cm, and pieces should be short enough to lie flat over the embers.

• The maximum quantity of fuel is approx. 2 kg/hour (max. 2 pieces of wood each time you re-stoke).

Lighting a Cold Stove:

1. A layer of embers is formed quickly when lit with 2 kindling tablets (or similar) together with approx. 1-1.5 kg of dry kindling. Place the kindling sachets evenly under the top layer of kindling.

2. Open the secondary air supply completely by turning the regulation handle beneath the door fully to the right. Primary air is not used when firing with wood.

3. After the kindling has caught fire, leave the fire door ajar so that the chimney draws well.

4. When you see that the chimney is hot enough to draw (after 5-10 minutes), close the door. After another 15-20 minutes, a thick layer of embers will have formed.

Refueling (Re-stoking):

5. Re-stoking should be carried out while embers still remain. Distribute the embers in the bottom, ensuring most of them are at the front of the stove.

6. Place 2 pieces of wood of 0.5 kg each and approx. 20-22 cm long over the embers in a single layer, with a distance of approx. 1 cm between them.

7. Open the air supply to maximum and close the door. The fresh wood will ignite within a couple of minutes. It is important that the fresh wood starts to burn quickly.

8. Once the fire is established, reduce the amount of combustion air to the desired position. Optimal combustion will continue until there are glowing embers. Always ensure there is enough air (oxygen) to maintain clear, lasting flames.

9. A new portion of wood can be added by repeating steps 5 & 6.

• The stove door should never be opened when the stove is being fired vigorously.

• To refuel, you must have a sufficient quantity of glowing embers and ash to ensure the new fuel charge will ignite in a reasonable period. If there are too few embers, add suitable kindling to prevent excessive smoke.

• Do not exceed the maximum amount of fuel specified in the manual. Overloading can cause excess smoke.

• Do not operate the appliance with the door left open except as directed in the instructions, as it can cause excess smoke.

• We strongly recommend that you do not leave your MORSO S11-90 stove lit at night. It harms the environment and constitutes very poor use of wood.

The following table shows the number of cubic metres of different types of wood (with 20% moisture content) required to equal the energy of 1000 litres of oil:

External Maintenance:

The cast surface of the stove is painted with heat-resistant Senotherm paint. It is best maintained by vacuuming it with a soft brush attachment or wiping it down with a dry, dust-free cloth. If the painted surface assumes a greyish tinge over time, it can be freshened up with Morsø spray paint.

Internal Maintenance – Glass Window:

If soot forms on the glass, it will typically burn away once normal combustion begins. If the glass becomes thoroughly covered in soot due to incorrect operation, it can be removed using Morsø Glass Cleaner. The glass must be cold when you clean it. Avoid stoking the stove with wood long enough to press against the glass when the door is closed.

Internal Maintenance – Gaskets and Parts:

Over time, the gaskets in the door will wear and should be replaced as needed to prevent wild combustion. Use the original Morsø gasket kit. Baffles and other internal parts are wearing parts and can be replaced if they are damaged.

Reasons for a sooty glass window:

• The fuel is too wet.

• The pieces of fuel are too big/uncut wood.

• The combustion temperature is too low.

• Insufficient air for the combustion.

Reasons for overly rapid wear of internal parts:

• The stove is fired too vigorously.

• Use of very dry wood (wood from old furniture).

• Too much soot on top of the baffles.

• Too much ash in the ash pan.

Cleaning the Stove:

Layers of ash and soot will form on the topside of the baffle plates. The baffle plates may be taken out of the stove for normal cleaning. When they are removed, you can access and clean the flue chamber above the baffle plates. Clean the baffle plates before reinserting them, and ensure they are properly put back in place. The chimney sweep must also remove the soot in the stove in addition to sweeping the chimney.

Ash Management:

There should be a layer of approx. 1 cm of insulating ash in the bottom of the combustion chamber to achieve a high combustion temperature. If the layer of ash is too thick, it can be brushed down into the ash pan. Empty the ash pan before it gets completely full so that the ash does not insulate around the grate, which would speed up the burn-through.

Ash Disposal:

In most cases, ash needs to be taken away by the waste disposal company. Because embers may be concealed in the ash for several days, it may be necessary to store the ash in a container made of non-flammable material before pouring it into a rubbish bag. Ash from a wood-burning stove is not beneficial as garden fertiliser and must not be poured onto soil if you have burned colour brochures or treated wood, as it may contain heavy metals.

• Use only dry wood: Use only dry (max. 20% moisture content) and untreated wood. The fuel must be split and 8 – 12 cm thick.

• Light correctly: Light with dry kindling (use 1 – 2 kg). Leave the door ajar and stay close to the stove during the lighting phase.

• Ensure a good layer of embers: Be certain to have a good layer of embers before refilling. The wood should light within 2 minutes. If the logs do not ignite it may, in an extreme case, cause the flue gases to ignite, which may pose a risk to material damage or personal injury.

• Refuel properly: When refuelling, use 2 – 3 pieces of wood, no more than 2 – 2.5 kg.

• Ensure adequate air: Maintain clear and yellow flames.

• Never burn overnight: Do not leave the stove burning unattended overnight.