I'e been trying to figure out a low temp DHW problem on a 10 year old boiler. I've replaced the right hand block, pump, diverter valve, DHW temp sensor, DHW plate heat exchanger, and flow turbine. I know there may be a scale issue on the main exchanger and I'm going to descale.
But, I've found that the DHW temp on display is wrong. The boiler is set for 140F. Input water on the cold side is 54F. I turn on one faucet with 1.2 GPM flow rate (both measured at the faucet and reported by the boiler) and let things stabilize. DHW temp on the boiler display is 126F. Actual DHW temp 1 foot off the boiler is 116F. With this flow rate, the boiler shows it is operating at only 50% capacity. If I open another faucet, flow rate is 2.4, boiler reports it's running at 100%, and temp doesn't change.
I went through and tested the water temp sensor resistance and it jives with actual water temp, but the display is consistently wrong at all temperatures. The manual says this might be due to a bad code plug, but seems like it's probably a bad PCB. Anybody run into this?
thx
But, I've found that the DHW temp on display is wrong. The boiler is set for 140F. Input water on the cold side is 54F. I turn on one faucet with 1.2 GPM flow rate (both measured at the faucet and reported by the boiler) and let things stabilize. DHW temp on the boiler display is 126F. Actual DHW temp 1 foot off the boiler is 116F. With this flow rate, the boiler shows it is operating at only 50% capacity. If I open another faucet, flow rate is 2.4, boiler reports it's running at 100%, and temp doesn't change.
I went through and tested the water temp sensor resistance and it jives with actual water temp, but the display is consistently wrong at all temperatures. The manual says this might be due to a bad code plug, but seems like it's probably a bad PCB. Anybody run into this?
thx
