I have a Takagi TK1 that's been in use for several years, so descaling is on my to-do list.

In principle, it's simple. Recirculate descaling solution through the unit, let it sit for some period, flush.

In practice, what's the best way to do that?
Is there a preferred (low cost) recirculation pump that would be recommended? (biggest question!)
Should I just detach the inlet/outlet connections and put new temporary fittings on to do the job?

Other opinions?