for various reasons i might just put in an electric boiler for the short term. Heat loss is only 25000BTU/hr so heat source options are limited.

How do these normally operate? Some of the manufacturers literature talks about 2 stage (ok i understand that) and outdoor reset (i understand that in principle but my design temps are only 110°F).

Would the boiler set point really adjust downward in mild weather?

Does the circulation pump cycle with heat calls or run continuously?

For simplicity sake would it be reasonable to consider three tiny electric boilers, one for each manifold? I am thinking the mechanical layout would be dead easy although there would be redundant components (not entirely a bad thing).

Thanks in advance for any information on how electric boiler only systems are designed to work.

John

One boiler. We design and install radiant floors using electric boilers including Electro and Thermolec. The smaller the load the less important the staging or ODR in terms of comfort and efficiency. For a temporary application, neither makes sense. Many of our radiant systems, both gas-fired and electric, modulate output on outdoor temperature and range from 70 to 95°F. Just finished a radiant ceiling retrofit designed to 100° DWT, running off an existing cast iron clunker, but ODR will be retrofit.

Pumps normally cycle with the boiler, but full time pump can be used depending on the design. We use ECM pumps on many designs.

Three electric boilers? Three expensive installations. They make zone valves and manifold actuators for this.

The electric boiler is just a tool. The trick is designing a system around them.

The question is really; how to design a radiant floor heating system?