Laars Endurance EBP110 heating issue

budalb

I am running into some issues with ebp110 and need some suggestions. When the room temperature set point increases in the morning, the water in the baseboard radiators is cold. The cold return slush quickly reduces the tank temperature of ebp 110, putting the boiler into tank charge mode and stopping the heating circulator. So it takes quite a while for the water temperature in pipes to rise for continous operation.

The issue makes room temperature rising very slow. Any suggestions? Here are more details with an examples.

Boiler set temperature (supply) 190
If tank temperature drop 40 below set temperature (190-40=150), boiler enters tank charge mode until supply temperature 5 below set temperature (185). In about 3-4 mins of tank charge mode, heating is stopped.

It only takes about 1-2 mins to drop tank temperature to charge mode when the heating resumes. So the heating system is on for 1-2 mins and stop for 3-4 mins, repetitively, until the system can sustain continous operation. In old days, the process takes forever.

I guees there are two approaches.

1) install a buffer tank to increase the thermal mass of the boiler so that the tank temperature won't drop quickly.
2) install a variable speed circulator so that the system flow rate is low enough in the beggining not to reduce tank temperature quickly.

Am I right? Thanks for your opinions!