As per the title, we have serious issues with our heating system. When we bought the house, it was fitted with a Randall 103, i.e. the wrong controller for a fully-pumped system. The only way to get the heating to work was to have the HW tank stat at 70deg. November gas bill was £135!
Engineer diagnosed the problems - wrong controls and broken 3PV, replaced these early Dec.
There now seem to be several problems:
1) Boiler is switching in and out every few minutes even if room/tank/both stats are not satisfied. E.g. tonight, heating on at 4pm, ambient 17deg. Set point 21deg, system reached only 19 deg after 4 hours. The boiler is *not* locking out.
What would cause the boiler to switch off if the set point's not reached? It seems to be taking more notice of the dial on the front of the boiler than the stats.
2) If CH required on its own, system fires up as expected and apart from problem 1), it runs until the programmer tells it to switch off. Same is true for HW on its own.
3) If BOTH CH and HW required, *sometimes* CH will stay on while HW is on, but usually CH goes cold, which is great fun on a January morning. The CH channel "on" indicator on the programmer (Salus EP200) stays on when this happens and the Rstat is calling for heat.
4) When HW program ends, 3PV does *not* make a noise or move. CH (if still required) does *not* come on. The only way to make the valve move and the CH come back on is to turn the CH to off, which causes the valve to move, then switch CH back to auto, which moves the valve again.
3-way valve is Salus 322, programmer is Salus EP200. Rstat is ECO RT3 (wireless). Even though the house is cold and the HW is only called 1hr am, 1hr evening (set to 60C) the system's using over 2cf per day.
Does anyone please have a clue what's going on?