Existing problem job

markel

I just walked into a nightmare job.

oil fired boiler with 3 zones (valves)

circulator installed on top of boiler supply (backwards)

1 baseboard zone, 1 indirect DHW zone

1 zone serving indirect tank for separate radiant system

radiant system has 3 -007 circ zones



according to owner, system never worked properly, so contracter altered system as follows:

rec room zone is in concrete slab with thick carpeting...Never heated properly, so contracter removed that zone from radiant side system & added to main system as 4th zone.

customer complained of lots of banging (I reversed circulator flow) now water flows properly through zone valves, however the  radiant zone has its own circulator, which is also flowing (backwards) when this zone calls, it short circuits the baseboard zone... I was originally just going to reverse the flow, but i don't think that will solve the short circuiting.

I think my best  cost effective option is to install  the circulator  as a 2nd circulator zone off the  boiler with  2 relays

any suggestions?

Paul Pollets

Sawzallectomy

I'd remove the near-boiler piping and start over. Low temperature zones on an oil fired boiler should have a 4 way motorized valve to prevent thermal shock, coupled to an outdoor reset control. Tekmar makes several models that will handle the mixing valve and motor, zone valves and indirect tank. Their schematics give several options for re-piping.