My house has three hydronic heatin loops; two are shaped like a ladder.
The baseboard radiators are plumbed with type M copper pipe.
I'm thinking about installing thermostatic radiator valves on the 'rungs' of the ladder; one loop will be left open.
- Will this cause excess pressure in the system, causing pipes to leak?
- Will this cause the pump to fail earlier?
- Any other concerns with doing this?
I'm curious as to why this isn't done more often, as the valves seem much cheaper than zone valves.
Best Answer
Excess pressure?
No. Residential circulating pumps can only produce limited head pressure.
Early pump failure?
No. Life expectancy of residential circulating pumps is not usually affected by changes in flow.
Other concerns?
Maybe, depending on your exact layout. Response time of wax motor thermostatic radiator valves is slow (20+ minutes) and restricted flow through partly open valves may distribute heat unpredictably where there are multiple radiators in series in a single branch (or ladder rung). From the Taco "Hydronic Zoning Seminar - Residential and Light Commercial Applications":
Also, depending on the type of boiler you have, it may have a minimum flow and heat delivery requirement. Too few thermostatic valves open within a zone may cause the boiler to not work well.