Plumber

Jemal

I want to install in floor tubing in the first two floors of a house and baseboard radiators on the top floor. What is the best way to achieve this given the higher temperature water needed for the radiators? I want to run heat everything with the same condensing boiler.

Rich_49

Do the math

and if you require help with the math hire someone who can .  A room by room heat loss is the first step to determine equipment size, tube spacing , supply water temps . 

Use a product like this on the upper floor ,   http://www.smithsenvironmental.com/ES_HeatEdge4cBro_SM_4.pdf and size it for using 120* or less but if you need to go as high as 140* with a 20* Delta T .  Panel rads with TRVs is a better option in my opinion . These can be piped to a manifold and all rooms will have same comfort level .

  depending on the number of zones you want or require will determine whether you need a buffer tank or not to eliminate short cycling of the boiler or you could use a mod / con that has mass for this , HTP Pioneer is a good choice .  Will you make domestic hot water with this boiler also is another question .