Hi
I have a Vokera Compact 25HE with DPS bouncing. Basically with any demand the fan runs, pump runs, all sensors ok and relevant switches closed, DPS closes, boiler fires. After about 20secs flame goes off, when I check the DPS it's open circuit, wait about 45s-1min, DPS closes and boiler fires. This is a continuous cycle and as you can imaging the rads take ages to get hot due to the cycling and hot water is intermittent due to this. New DPS was fitted but same problem. I read a few threads about the Venturi being blocked so we have checked them and the silicone tubes and they are not blocked or broken. Any ideas? it's defo the DPS bouncing causing the flame to go off/on..... just can't figure out why. We disconnected the shorter tube from it's venturi as we discovered the longer tube was the one activating the switch then fired up the boiler and it ran fine, no switch off so the conclusion is some sort of difference in pressure (being a DPS!) between these two ports is causing the 2nd port (shorter tube) to pull the DPS off... but what? Flue looks ok and no obstructions. Been running fine for 3.5yrs......
Any help appreciated
Thanks
I have a Vokera Compact 25HE with DPS bouncing. Basically with any demand the fan runs, pump runs, all sensors ok and relevant switches closed, DPS closes, boiler fires. After about 20secs flame goes off, when I check the DPS it's open circuit, wait about 45s-1min, DPS closes and boiler fires. This is a continuous cycle and as you can imaging the rads take ages to get hot due to the cycling and hot water is intermittent due to this. New DPS was fitted but same problem. I read a few threads about the Venturi being blocked so we have checked them and the silicone tubes and they are not blocked or broken. Any ideas? it's defo the DPS bouncing causing the flame to go off/on..... just can't figure out why. We disconnected the shorter tube from it's venturi as we discovered the longer tube was the one activating the switch then fired up the boiler and it ran fine, no switch off so the conclusion is some sort of difference in pressure (being a DPS!) between these two ports is causing the 2nd port (shorter tube) to pull the DPS off... but what? Flue looks ok and no obstructions. Been running fine for 3.5yrs......
Any help appreciated
Thanks