The never-ending mandelbrot of a single change

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So, when we made the decision to switch our boiler to one available off-the-shelf (kinda) locally (it had to be ordered from the warehouse – but it was a next-day job); I knew that it might result in some changes. First, I knew that the new boiler has a 2″ flue, and the flue we installed was 3″. But slapping a reducer on it was acceptable, although I was unclear until it arrived whether that was an option you could switch on the boiler, or whether you had to buy one. You have to buy one; I now know having stared at the manual and the boiler in person.

But the ever deepening spiral of things that change as a result has just continued and made today a very frustrating affair.

To be fair, partly it was frustrating because I rapidly realised that I couldn’t lift the boiler into position. I did lift it – both into the house and in an experimental “can I lift this” way. It’s only 30kg (66lb), but it was instantly apparent that “this was a terrible idea” was the title on the “Kate tries to mount the boiler by herself” blog post.

So instead I did what I could.

So the morning had started well enough, I collected the boiler and the fitting kit, and bought some of the bits from Ferguson. Then I headed over to Home Depot to get more – mainly because Ferguson don’t appear to post their prices in the store – you find out at the counter how much things are, and I’m not monied enough to think that’s a reasonable way to go about things.

Having got to the house, the first job was working out where to put the mounting for the boiler. Now, the first thing is, unlike the nice Bosch boiler we were going to get, which comes with a full-size fold-out sheet with drill hole marks, and pipe alignment marks that you can just stick on the wall and then have-at-it, the Navien instead comes with a manual that has some – but not all of the measurements you might want. For example, the minimum distance between the top of the boiler and the ceiling – in the manual. The distance from the top of the boiler to the hanging clips on the back of the boiler? Not in the manual. Having spent some time (and tea, and an Eccles cake), I realised that the house’s flue also no longer lines up with the newly chosen boiler’s flue. And that I would need to shift the flue across to line up. And that means… that the boiler has to sit lower to allow room for that sideways shunt.

After some experimentation and footling, plus a bit of “well, let’s add an inch or two spare”, I concluded that I knew where the hook was going, and lopped the flue pipes off (leaving plenty spare), marked up the walls and prepped to drill.

Incidentally, the silly little junior hacksaw is because we never took the main saws out of the attic…

I mean, it’s not scary at all drilling into our walls. No.

Lime’s not fragile. Not at all. Noooo.

Okay, so holes drilled, mounting bracket on the wall. Time for some more checks.

Now, I opted to get the connection manifold, partly because I’m a big scaredy cat, and partly because I am not that good-a-plumber. As any plumber looking at the rats nest that is the cold/hot water manifold will tell you.

Anyhow, the manifold is clearly intended for American size houses. None of this 3/4″ m’larkey that makes up the rest of our manifold. Oh no, no, no. That’s not big enough. It turns out the heat/return/mixing zone pipe is a massive 1.25″ pipe. I don’t even have any connectors that big. Home Depot don’t carry them. (I assume Ferguson do, since the manifold is an actual off-the-shelf item).

It’s f’kin HUGE. We could more or less just bathe in it. Frankly, we could more or less have skipped the underfloor heating and just used this. I think it nearly doubles the circulating volume of our heating system.

I might be exaggerating, but just a little.

Anyhow, so I have this massive manifold sat on the floor in front of me and there is the slow dawning realization that there is no way on this earth that it’s going to fit above the aforementioned rats nest hot/cold water manifold.

After much measurement, repeated admonishments to myself to take this as a learning experience, I concluded there’s nothing for it but to cut the manifold out and move the whole damn thing down as low as it can reasonably go.

After staring at it some more I headed back to Home Depot and bought a bunch of bits that I felt would be required to achieve reconnection and rerouting stuff to feed the boiler.

Then I started taking the manifold out. After a while it became apparent that I don’t quite have the strength to just cut off all the pipe-clips that hold the PEX together. And then I got my grump on, headed back to Home Depot for the third time to buy the PEX clip remover, which it turns out is just a very overpriced socket wrench with a slightly sharp doohickey on it that slides over the crimped bit of the clip and allows you to snap it off. Then begins the battle to remove the pipe from the PEX tubing (because I don’t really want to waste that many PEX bends).


As 5pm rolled around I decided I’d had enough for one day. I’ve managed to reconnect a grand total of three of the 12 circuits, and will be sorting out the rest on our next visit to the house. Along with hopefully mounting the boiler and hooking it up.

We still need to connect the flooring pipes to the manifold, hook all that up and pressure test it too. Unlike the hot/cold water system which shouldn’t be too bad, the heating will need a good flush through as it’s got a lot of copper in it – much of which is soldered using lead-free solder (which I’ve not used before) and proper solder joints (which I’ve very rarely used before – I normally use Yorkshire joints, aka solder-ring-joints, because I’m lazy and…uh, yeah, that’s it really).

We won’t be able to hook up the hot water side until Tuesday anyway, because the hot-water / cold water feed valve kit isn’t included, and is, it turns out, complicated, and so I ordered it after the fact. Adding another $90 to this journey.

I continue to wish that we’d opted for electric underfloor heating, or a heat-pump hydronic system, although I still can’t think of a way it could have worked (other than building it a little shed on the end of the building, or completely changing the interior layout, or perhaps having the hot-water tank for the heating in one of the attic voids, which seems crazy).

Installing gas, right now, seems like such a terrible environmental idea (it really is); still, we’ve decided pretty much that we are going ahead with solar, we think, so perhaps we can offset it a bit.

The most frustrating thing about this whole installation process, though, is that it means we can’t get our floor down for 2 more weeks (it’s a two-day, both of us job). Although I guess I might be able to do the bathroom floor earlier, since it’s tiled. And as soon as the hydronic bit is approved, we’ll be able to cover it. Meh. Maybe that’s a plan.

Anyhow, I’m less grouchy now and more tired. More news from the field of crazy DIY housebuilding after the weekend, I suspect.


Kate's allegedly a human (although increasingly right-wing bigots would say otherwise). She's definitely not a vampire, despite what some other people claim. She's also mostly built out of spite and overcoming oppositional-sexism, racism, and other random bullshit. So she's either a human or a lizard in disguise sent to destroy all of humanity. Either way, she's here to reassure that it's all fine.