Cast Iron Rads not heating

Ohioboiler

I added a radiator and rerouted s/r lines on another and now they won’t heat. I assume there is an air lock, but I am having trouble purging the lines.

I have a Lochinvar combi, alpha 2 set on auto adapt, and cast iron rads with TRV. The maniford has purge and fill valves. I have given up on the company that installed the system as they have come out several times and claim the problem is that I don’t have a central thermostat, but I think the TRV are better.

Any thoughts? If everyone agrees it needs purges, can someone walk me through the steps? I’ve included photo of the near piping, the manifold and the TRV. Thank you.

Paul Pollets

Set your pump on speed 3, not auto adapt; turn all TRV's to 5 and turn up pressure in the boiler to 20-25psi while calling for heat and purge. When radiators are warm, put the pump on auto adapt and reduce boiler pressure to 12-14. TRV's can be adjusted when purged.

Ohioboiler

Thank you for the quick response. I’ve never adjust the pressure from the boiler, is it explained in the manual, or is it a trick of the trade?

Or would it be better to run a garden hose to the fill valve on the manifold and purge each radiator individually?

Paul Pollets

the boiler has a pressure relief valve that will discharge at 30lbs. so hooking up a garden hose is not recommended. You'll have to learn how to turn up the pressure using the fill valve.

mattmia2

the pressure reducing valve is in the middle just after the water filter. the knob adjusts the pressure, the gauge will show you the pressure.

Ohioboiler

Thank you. With primary/ secondary piping and shutoff valves on supply/return ports of the manifold, I thought I could use the fill/purge valves. Regardless, I’ve tried purging several times and Have had no luck. How often does a Return line get blocked? I can purge air and water from the bleed valve on rad, but only get a trickle of water and a few bubbles from the return line at the manifold.