Technical data

The Midimat should be commissioned by a competent engineer. Before commissioning the appliance,

the whole gas installation including the meter MUST be purged and tested for gas soundness in accordance

with IGE/UP/1.

Caution: Open all doors and windows, extinguish naked lights and DO NOT SMOKE whilst purging the

gas line.

The entire water system must be thoroughly cleansed and flushed to remove debris, flux residues etc

before opening the boiler isolation valves and filling the boiler. Particular care must be taken where the

appliance is being retro-fitted into an old/existing system, as system silt or magenite can be very damaging

to the new boiler.

Following cleansing and flushing, the system must be dosed with a good quality water treatment to

prevent corrosion and the formation of scale.

Failure to observe these requirements will

render the guarantee on the product void. Cleansing, flushing and water treatment

must be carried out in accordance with the requirements of BS 7593:1992.

The return pipework must include some method of filtering or straining. The filter or strainer must be

fitted with isolation valves to allow easy cleaning with the minimum amount of water loss and water

replenishment.

Note: A low water pressure switch is included in the boiler and interlocked to shut the boiler down in the

event of the water pressure falling below 0.5 bar.

Note: TheMidimat boiler has heat exchangers fabricated from 316L stainless steel.

It is most important that the compatibility of any flux is checked with the flux

supplier before use, and that any flux manufacturers recommendations are strictly

followed with regards to use in conjunction with stainless steel.

6.1 filling the boiler

TheMidimat must be filled by a competent person using one of the approved methods in BS 6644:1991.

Fill the installation to the system design cold fill pressure and vent the boiler via the air release valve on the

boiler primary heat exchanger. See section 4.6 'filling the system' for guidance.

6.0 commissioning

& testing

S1 Flow Temperature Sensor

S4 Return Temperature Sensor

S5 Domestic Hot Water Temperature Sensor

S6 Outside Temperature Sensor (KKM2)

S7 MR03 Mixed Flow Sensor

AF Outside Temperature Sensor (Boiler)