Wood, coal and wood-gasification boilers are long-burn appliances, so their flue is cleaned twice in the heating season. Cleaning one flue costs from €100, with the certificate and call-out in Riga and the Riga region included. Write the boiler type and its output in the form, if you know them.
Two cleanings a season: why a boiler needs more than a stove
A boiler does not store heat the way a masonry stove does: it passes it straight to the heating system, and the smoke in the chimney is cooler. That is why the regulations require boiler flues to be cleaned by 1 November and again between 1 November and 1 March. If the boiler runs all year, for example for hot water, soot builds up in summer too.
Cabinet Regulation No. 238 “Fire Safety Regulations”, point 68: the flue of a long-burn solid-fuel heating device or appliance is cleaned before the start of the heating season (by 1 November) and once during the heating season (between 1 November and 1 March of the following year). Source: likumi.lv, checked 04.11.2026. Regulations checked 04.11.2026; from 2 January 2027 they will be replaced by new fire safety regulations, which we will check as soon as they are adopted.
The boiler type decides what builds up in the flue
| Boiler | What builds up in the flue | What we look at |
|---|---|---|
| Wood boiler with top combustion | soot and tar, especially with damp firewood | the upper part of the chimney, the flue pipe |
| Wood-gasification (pyrolysis) boiler | less soot if it works with a buffer tank; a lot of tar if it smoulders | whether the boiler is running in reduced mode |
| Coal boiler | fine, heavy ash and sulphur compounds that, combined with moisture, damage the masonry | joints, condensation, chimney base |
| Combination boiler (wood and pellets) | deposits from both fuels | bends in the flue pipe and the T-piece connection |
| Pellet boiler | fine ash and condensation | bends in the flue pipe, moisture in a masonry chimney |
Pellet boilers have their own quirks because their smoke is cool and damp: pellet boiler flue cleaning.
How we clean a boiler flue
- Boiler cooled down Stop heating the boiler the evening before. Before the work we check that there are no glowing embers in the firebox.
- Flue pipe We disconnect the flue pipe from the chimney or open its cleaning door and clean it with a brush. A flue pipe with two bends often holds more soot than the chimney.
- Chimney We clean the flue from the top or from the bottom with a brush that matches its diameter and material.
- Chimney base and door We take the soot out of the chimney base through the cleaning door and check the door seal.
- Draught and certificate We reconnect the flue pipe, check that the joints are tight, check the draught and draw up the certificate.
The inside of the boiler (heat exchanger, turbulators, flue gas chamber) is cleaned according to the manufacturer's instructions, usually by the owner or the boiler service. We mention it because a clogged heat exchanger also reduces the draught and increases the amount of soot in the chimney.
If you replace the boiler
When a heating boiler or stove is replaced with another one, the flue and ventilation must be checked for suitability before the new appliance is used. A technical condition inspection certificate must be drawn up stating whether the new appliance may be connected to the flue. The most common problem is an old, wide masonry flue for a modern boiler with a lower output: the smoke cools in it, and condensation and tar form. Then you usually need chimney lining, and the certificate is drawn up as part of the chimney sweep's condition report.
Gas boilers have other deadlines and their own requirements: a brick flue once a year, a lined or metal one once every two years, and if the appliance has been disconnected for longer than six months, an extraordinary check is needed. More on this: chimney check for a gas boiler.
Cabinet Regulation No. 238, point 70 (gas appliances, extraordinary check after a break of more than six months), point 71 (gas and liquid-fuel flues) and point 79 (replacing an appliance, certificate on whether the appliance may be connected to the flue). Source: likumi.lv, checked 04.11.2026.
How much boiler flue cleaning costs
Boiler flue cleaning costs from €100, usually €100–130, with flue pipe cleaning, the certificate and call-out in Riga and the Riga region. The price goes up with a long or winding flue pipe, thick tar and difficult access to the chimney head. All prices: prices.
Sources
- The flue of a long-burn appliance is cleaned by 1 November and again between 1 November and 1 March (68); gas appliances (70); gas and liquid-fuel flues (71); replacing an appliance (79) checked 4 November 2026
- The definition of a flue includes the flue duct, the chimney stack, the flue channel and the flue pipe (63) checked 4 November 2026