Hello, I just bought a house with a tankless heater and a recirculating water/heater system. The burner on the heater only kicks on if there's 0.8 gpm running through it. For some reason it keeps turning itself off. When I check the remote on the tankless is showing the flow rate at 0.5gpm. I'm thinking either the filter is dirty (cleaning that tomorrow) which is throttling the inlet water a bit, but I wouldn't think that would be enough and it wouldn't explain why it's running intermittently. I'm not sure if the pump is working or not either. I toggled it on and off but couldn't tell a difference. Any suggestions?