I am looking for advice re a 25 year old system which used to be serviced by British Gas when I could afford it. The problems are many - radiators pinholing and needing regular replacement despite inhibitor, furthest radiator from pump and zone valves (in airing cupboard) staying cold after refilling, although it eventually seems to bleed itself after a few weeks each time. The upstairs radiators all get warm when the hot water alone is switched on as well as when central heating is on as well - the reason why I replaced the zone valves. I have replaced several gate valves with Pegler versions as some of those were seized open, would not close properly, or just spun round as the worm drive had sheared. The boiler is a Baxi Bermuda back boiler and there are seven radiators in the house, a mid terraced cottage. All radiators have TRVs and there is no room thermostat. There are two Honeywell zone valves, recently replaced by me, in the same position and with the same flow direction as before. I don't know if BG ever replaced these, but there is one end capped pipe indicating perhaps that the layout has been changed. I do know that BG replaced the circulator pump, because my other half was at home when the two BG men came, and she said they spent all day with much cursing and frequent phone calls back to the office (obviously not the modern laptop using type of fitter). They put the Grundfos pump in a horizontal position, with the front slotted screw nearly upright - a position with a cross through it on the leaflet that came with the pump. The flow is toward the two zone valves, but the flow arrows on both of the zone valve bodies are in the opposite direction, towards the pump. My query is this: I have a feeling that BG fitted the pump with the flow reversed, as they were not familiar with a system where pump and valves are fitted on the return side from the boiler. The pump gurgles quite bit, and because there has been air in the system, because of the installation position I imagine the bearing on the upper end of the shaft may have worn out. I have a new pump ready to fit. I would like an opinion from one of the knowledgeable people on this forum whether I should fit the pump with the flow the same way as the zone valves (I think on the return side from the boiler from my tracing of the pipes, but obviously I am no expert) or reverse the zone valves and keep the flow direction the same for the pump, but fit it in accordance with manufacturer's instructions. I have uploaded a photograph which as you can see shows that the pipework is a bit of a dog's breakfast. BTW I have looked all over the forum and can't find exactly the same problem as I have, although there are many queries about dodgy pipework, suggestions about combining feed and vent pipes at the header tank in the loft etc. Incidentally over the last couple of years I have used gallons of Sentinel cleaner, which usually effects an improvement. Any suggestions gladly received.
Chris
Chris
. If the slot screw was dead upright - it would be wrong : I love to slag BG, but I can`t on this occasion. Just checked on Grunfos website - Pump spindle horizontal or above . Not dropping below , or dead vertical.
