Hi folks.

We are no further forward with the solar hot water heater problem - I'd no idea plumbers were so skilled at disappearing off the face of the earth. It's like living in Alice's Wonderland where you can see the White Rabbit coming your way and then he just goes right past muttering about the time . . . and you wonder where the hell he went . . .

Anyway, I've found this website a treasure trove of information and can see other people having woes just as wuss as mine. And having lost lord knows how much hot water through the header pipe/exhaust(?) by this time, I got to wondering why the blue blazes it isn't positioned further down in the tank where it would vent colder water and leave the hot where it is? See the attachment.

I suppose you will tell me . . . . . . .

Linkback: https://www.plumbers.nz/q-and-a-hot-water-cylinders/44/hot-water-cylinder-design/1477/

Wow! Of course. I knew there would be a good reason for it.

Good to get the actual figures involved. Thank you. I'd no idea the conversion is so huge. I'm all the more concerned then that we have steam coming back into the cylinder from the collector. It certainly makes it jump around and scream like a pig getting its throat cut.

And can you tell me about this valve that they were considering putting in the header pipe instead of trying to discover what was causing the problem? It didn't sound like a good plan to me at the time and it is even less so now that I know this interesting fact.

I reckon we were lucky when our header pipe got blocked by a mud dauber wasp nest. I expect the solid mud liquified when it got scalded. We had the wasps come through in the hot water - dozens and dozens of them. This was ages ago - before we had the solar installed. I've always been concerned in case it happened again. It's kinda hard to get up there to check!

As a matter of interest, how do you lengthen a header pipe? It is inside a  white drain-type tube anchored to the roof. Looks a tricky sort of a job?

Now there's an offer that would be hard to refuse. I'll discuss it with you privately. But thanks. Thanks very much.

This question (about sinking the header pipe) was so dumb I can hardly believe I asked it - after all the air and steam bubbles I've had in this tank! A sure sign that this situation is getting on top of me and I no longer think straight.

Hello squirrel. I do hope squirrels and badgers get on!

Yeah. I'm embarrassed about this one. Too tired. And too many gins perhaps. Talk about being driven to drink!

But moving on.

I've still obviously got a hole in my picture here - possibly because you guys speak plumb and I don't. It's this business of "stagnation" in the manifold when the pump is switched off because the temp. is 85°C in the HWC. In plain english can you tell me exactly what goes on in there when the Caleffi vent is not working and the steam can't get out. I think I know, but I'd like someone to tell me I'm right. In terms of volume, pressure and temperature please. Even if it's only one litre left behind in the manifold - this is one hell of a lot of steam to be trapped. And of course it isn't. But what happens before it gets out of my header pipe?

Thank you

More questions if you can answer that one. Any takers?

Thanks guys.