Operating instructions

Troubleshooting 10

We reserve the right to make any changes due to technical modifications.

Operating instructions RC30 programmable room thermostat • Issue 02/2006

Why do the radiators

get (too) hot when the

outside temperature is

relatively high?

If you have a heating system with a heating circuit and no mixer

valve, this is normal (see "What are heating circuits?", page 9).

The circulation pump only starts up when the boiler reaches a

predefined flow temperature. If the flow temperature is higher than

the temperature required on the basis of the outside temperature,

the radiators may get hotter for a short time. The heating control

unit detects this and quickly responds accordingly. Do not adjust

the thermostatic valves on the radiators and wait until the set room

temperature is reached.

In summer mode, radiators can heat up in certain circumstances

for a short time: The circulation pump is started up automatically at

a predefined interval to prevent it from blocking. If the pump

happens to be started up immediately after DHW heating, the

unusable residual heat is dissipated via the heating circuit and the

radiators.

Why does the heating

system pump run

during the night, even

though there is little or

no heating on?

This depends on the setting chosen for night setback by your

installer (see "Why do I need a heating program?", page 8). Please

ask your installer about the setback mode setting.

– Total shutdown: The heating system (and therefore also the

pump) is automatically switched off in night mode. If the

outside temperature drops below the frost protection

temperature, the pump is automatically switched on by the

"Frost protection" function.

– Reduced room temperature: The pump continues to run

even if the heating is reduced, in order to maintain the lower

room temperature.

– Change between total shutdown and reduced heating

subject to room temperature or outside temperature: The

heating system is switched on automatically if the actual

temperature falls below the set value. The pump then starts up

too.