GV Boiler(MK)

Mike Kraft

Walked in the door and I was swept away with the heat!Actually the complaint was the HO"s could not get the heat up to 75*-80*.Senior citizen bros. and they like it a bit warm.I installed the system around 10 years ago.

It is a GV 6 (yes I oversized it) and has three zones.This is a series one and they are on series four now.The system is doing everything it is built to do.I was scratching my head.Almost ready to leave and I ran to the truck to start shooting some temps @ the boiler with my laser.

This boiler has a thermostatic mixing valve and a boiler loop pump(primary).The system side is actually the secondary.Boiler flow is sent straight to the system and also dumps back to the TMV as it needs flow.The laser revealed that the system is getting 195* water right to the point of connection with the secondary.At that point I am getting 155* water.

I am shooting at the TMV as my problem.My assumption is that it is in the closed position and not allowing any return flow through the boiler and mixing down the system water.

Any similar experiences out there?I am not sure how to trouble shoot the boiler pump.Its hot in there and not sure if its pumping or not.How is this done with an amp meter please.

cheese

Steve Miller

GV's

To trouble shoot the pump just drain the system and pull off the cartridge of the pump and check out the impeller and dry fire it for a quick sec. The thermostat can be a pain to get to sometimes. Use some penetrating oil and soak the threads of the plug. You may need a 24" pipe wrench and a back up wrench to remove the plug to get to the thermostat. It looks just like an automotive one and they open at 140 degrees. don't relace with an automotive one because they have holes drilled in the body so they can be a certain amount of flow thru them before they open. Your Weil McLain rep should have a replacement on hand. Good luck!

Steve M.

tim from Reed Wright

gv boiler

yes, have had to replace thermostatic elements on the gv and the Burnham xg boilers. I think they are a 5-10year item as far as I can tell.

Chauncey

w/m p/n 382-200-370 m-v repair kit