Thermostats

This is a thermostatic, chain-controlled combustion air regulator designed to regulate solidfuel heat sources as coal-fired boilers, wood-fired boilers etc. Its metal construction and a composite head ensure good resistance against high temperatures and mechanical damage. The thermostatic element used guarantees precise operation and long service life of the regulator. The regulator has a standard lever of 120 x 145 mm, 120° bend, its regulation range is 30-90 °C and max. chain load 0.8 kg. It keeps the heating water temperature at the value set by means of a rotating knob and can be easily installed to any boiler type (having a female 3/4“ sleeve), either horizontally, or vertically.

Regulator installation:
Screw the regulator with its 3/4" outer thread into the boiler socket with 3/4" inner thread. Seal the thread (e.g. with Siseal sealant, Teflon tape…). Turn the regulator so that for horizontal installation (a) the protrusion for bar placing pinpoints downwards, for vertical installation (b) it pinpoints to the front, and for vertical side installation (c) it pinpoints upwards. Remove the plastic transport tube and insert the hole-free end of the hexagonal lever in its place. Tighten the screw in order to fix the lever in such a position that its free end is above the chain lug or fixture on the boiler door and the lever is as close to the horizontal position as possible (as much the hexagon allows). Attach the chain to the lever opening by means of the bigger hook fixed to the chain. Pass the other chain end through the fixture on the boiler door and hook this free end on the hanging chain. Check if the chain is hanging freely and the lever moves freely (when turning the knob). When the regulator is installed in (a) position, the white scale is valid. For installations in (b) and (c) positions the red scale is valid.

Regulator calibration:
Fire the boiler with door manually open. Set the regulator knob to 60. When the water temperature reaches 60°C, let it stabilize for a couple minutes and then adjust the chain fixture so that the door gap is about 1-2 mm. Now you can select the desired temperature. If the real boiler temperature was lower during stable operation than set, shorten the chain, if the real temperature was higher than set, prolong the chain. Please take into account also other factors that could influence the temperature inside the boiler disregarded of the regulator - esp. the quantity of fuel and ashes inside the boiler, position of the secondary-air flap, thermal lag of the boiler and of the whole heating plant.

We sell the RT2 Draft Regulator under code 5853