Dear forum,
I've an open (gravity) CH system supplying radiators only (AGA does the HW separately). It's a Vaillant Ecotec 435 installed 2018. The walls are v thick and prevented wireless thermostat signals so a plumber bypassed the thermostats a year ago. We have TRVs in all rooms apart from the lounge which has no valves (re safety for the pump). A year later the heat exchanger has failed. The plumber who identified this said likely because the boiler was calling for heat permanently, but also said the exchanger was full of debris. The system has had a magnetic filter for years and the water, when drained off, looks very clean. We live in a hard water area. I put inhibitor in once (I know I should have done that more). My question is "can the exchanger damage come from bypassing the central thermostats or is it more likely that it is limescale?". I thought continuous heating at a lower temp was inefficient but not boiler-damaging. The boiler intermittently locked out (F83) for the last year before failing. Many thanks indeed for any advice.
I've an open (gravity) CH system supplying radiators only (AGA does the HW separately). It's a Vaillant Ecotec 435 installed 2018. The walls are v thick and prevented wireless thermostat signals so a plumber bypassed the thermostats a year ago. We have TRVs in all rooms apart from the lounge which has no valves (re safety for the pump). A year later the heat exchanger has failed. The plumber who identified this said likely because the boiler was calling for heat permanently, but also said the exchanger was full of debris. The system has had a magnetic filter for years and the water, when drained off, looks very clean. We live in a hard water area. I put inhibitor in once (I know I should have done that more). My question is "can the exchanger damage come from bypassing the central thermostats or is it more likely that it is limescale?". I thought continuous heating at a lower temp was inefficient but not boiler-damaging. The boiler intermittently locked out (F83) for the last year before failing. Many thanks indeed for any advice.
