Peaklander

My decking was installed over twenty years ago and is in great condition. It is exposed to sun and wind (it's about 1m above ground level) and I think this helps. The piers sit onto concrete pillars in the ground (holes drilled with a huge auger). I treat it every few years with Hicksons Decor wax (sadly now ceased production).

I'm late to the thread. I have a pair of Sunsynk 3.6kW inverters in parallel. They provide the 'signal' for island mode across a volt-free contact, if you have also ticked the box in the settings to enable the feature. You monitor this with the external contactor that has been mentioned, letting the contactor couple the N & E when island mode is signalled (during an incoming power loss). On some Sunsynk inverters I believe that the VFC closes on island-mode but on my smaller inverters it opens. Therefore I need to use a normally closed contactor pair, so that when the contactor drops out, the N-E connection is made. As for providing a local earth, you need to supplement the DNO's earth because during a power loss you can't assume that their's will remain. So assuming that you aren't already on a TT system with your local earth rod in place, you need to provide one. This can stay in circuit and does not need to be switched out in normal operation. This IET article refers but here's a diagram from it... https://electrical.theiet.org/media/1549/earthing.pdf

Yes, I posted a pic of the inlet side of the pump but said that I didn’t have one of the H. The pipe was cut out and the crud cleaned out and then it was connected back in. Plumber #2 did that and I was cleaning the header tank.

Big thanks to @marshian for sharing the details of the old pump that I sent him. It really does explain a lot. To recap, I’ve not had any involvement with my parents’ heating until recently. So I’ve no idea if any inhibitors have been added over the years. It was another family member who noticed that the rads weren’t getting warm enough and as I live closest, it was me that went to look. That was after a plumber had been and suggested a failing pump and possible ‘air-lock’. Venting over wasn’t happing as far as I know, until I replaced the pump and even then it wasn’t noticed immediately. It had been drained so that a couple of trvs could be changed. Refilling was slow as we couldn’t remove the air easily. Only when plumber #2 and I decided to try a flush did we then see the vent-over happening. He didn’t comment on the short height of the U though. As we had enough heat for Christmas and NY I waited and called him back to open the H pipe. That was after plumber #3 quoted £5k to replace the whole system with a combi “the only way to fix it”. So to conclude, a bad design that somehow had never had vent-over and poor maintenance of the system which slowly filled with crud until a better pump highlighted the issues. I would never have got here without the help of you on here. Thanks to all.

It’s yours. Let me know what you want to do.

Yes 28mm around the bottom of the H on the boiler flow to pump and 22 up to vent with 15 down. i don’t know how long it has been since a drain-down or what chemicals have ever been in.

Yes got one.

Hi, here's the update. We cut the H pipework out, releasing it on the top side of the pump inlet valve. Popped a hosepipe below the cold feed isolating valve and emptied and cleared the header. There was plenty of gunk just in that, obviously most sitting on the bottom and sides under the water level. The inlet side of the pump was choked though. I don't have a pic of the H pipe as I was in the loft but that did have residue on the pipe walls. After this was re-instated the partial refill that was needed seemed to go better than previosuly and there was no pump-over at PP2 pump setting but still a little at full bore. So I asked plumber to lift the vent which he did. I'd already told him that I didn't want to retro-fit a pressurisation vessel. There was no pump-over after that at CC3 but in fact I left it at PP2 and all was well. The header had got some brown water in again from that brief pump-over and so I'm resigned to another full drain and flush/fill - but not until the summer. It has some Fernox P3 in for now. I need to leave it and give my parents relief from the to-ing and fro-ing. Thanks again guys for your sage advice and comments. It has been very helpful and gave me confidence to stand my ground and not do the pressurisation and certainly not rip the whole lot out and replace for £5k

A quick question, if you were me, would you still replace / inspect if possible, the H pipework? I don't think I now need to introduce the pressure vessel in place of the header. I'm planning to lift the vent pipe U and drain / refill after cleaning the header.

Plumbers 2 & 3 did. Don't know about #1. Thank you for all the help. This thread proves that often all of the detail is needed before a cause can be found.

Yes well it wasn't me it was Plumber #1 that said to swap the pump and sometimes I do listen. It can be a fine line to tread when a DIYer interacts with a tradesman. 😊

I didn't try it earlier because I was distracted by my Dad. Later I felt that maybe PP1 will be too slow and I can't be there to check over the next few hours. So I have come home to go to a 50th wedding. It will be good now until Tuesday when I am going to be steered by what Plumber #2 wants to do. However it could be as simple as lowering the water level. I did bend the float arm but couldn't bail any out as that's when Dad felt odd and I had to check for stroke and heart (I am not a medic). Also there is scope for the vent to be raised. Maybe that's all we end-up doing on Tuesday.

Yes the yellow leds flash on those variable speed modes - just needed to catch it right with the phone otherwise they are OFF! I haven't gone to PP1. I will leave until Tuesday and I suspect that Plumber #2 will want to remove the tank as I said. I think I can risk that. Screwfix have the parts ready for me to pick-up. My job will be to bail-out the header although as it's circulating around anyway, perhaps I can let most drain out first and then bung it up.

Ok some pics plus my father is having some sort of issue which I’m keeping an eye on. This is the first setting and the water flow over. This is PP2 with reduced water that sounds worse than it is. That just means I should have looked and not listened. There is scope to lift the height of the vent. Edit. Obviously the water colour is still not good and it will need a further clean.

I changed the pump and I will double-check the valves when I go there this morning. Plumber #2 says that they are very fragile, having sat there for years and they can break when operated.