Hello,
I have been converting my gravity HW and pumped CH to a fully pumped system with the help from everyone here. I would like to thank everyone who has helped me so far.
Someone told me to check with my boiler manufacturer whether it could be fully pumped and whether I needed an overrun and bypass valve. The boiler is made by Mistral. They have no internet presence but are based in Telford. They posted me a manual for my boiler. It talks more about siting the oil tank and flue than the plumbing but it does mention being either gravity or pumped, so there's no obstacle to my conversion in that regard. It does not say anything about overruns or bypass valves, so I haven't fitted either.
I replaced the old pump with a smart pump. I haven't had any sucking of air into the system so I have not put an air separator in, only because I had filled it before these were mentioned. Anyway, it seems to be working fine without one.
What setting should I set the pump to? The old one had three positions and was set to the third. Does it need to be that high? I realise that if it is set too high it will suck air into the system or pump over but on the other hand, won't the rooms warm faster if the water is circulated quicker or is that a misconception?
Is the setting that important with a smart pump? After all, if I set it to number three, will it turn itself down if this is not needed?
What bonding, if any, should there be at the boiler? There was none before I started work, except one earth wire to the incoming oil supply (small copper pipe: 8mm?). This is a thick earth wire that is buried in the plaster. It looks as though it goes up the wall and through the ceiling direct to the CU.
Unfortunately my cable finder developed a fault and no longer detects anything and I accidentally drilled through this wire when fitting the CH wiring box! The copper wire is ok; I have only scraped the plastic from off the side but I think it best that I should replace it. What size of cable do I need and should I bond it to any of the other pipe work at the same time?
The T&E and the cable from the thermostat is inside metal conduit; it's a shame they did not enclose the earth wire as well.
Those terminal boxes are a nightmare! I wired all the various valves, pumps, boiler, thermostats, etc and found that the last terminal would not screw tight! Is there a trick to fix this or do I need to unwire everything and start again with a good one?
Thanks.