Recent content by CarloHeatingEng

I'd leave that plug alone, as the pump's inside the boiler casing. It's pretty standard for the fitter to come back after a pump change, so get him back out to sort the noise. While he's there, I'd ask him why the old one failed. What does your pressure gauge read, cold and with the heating on...

Legend!

Cheers, appreciated! Yes, Gas Safe registered. How do I go about joining the CC?

All good! Definitely a good shout.

Fair point, it's not always a full rupture. Water at the Schrader can be a pinhole that still holds for a few minutes on the bench, or water that's crept through the diaphragm over the years and collected on the air side, especially with the valve at the bottom like the Viessmann. A 5 minute...

Serviced two weeks ago is a reason to ring whoever did it, not a reason to rule the burner out. Ask them back and tell them exactly what you told us: since the power went off for the meter, the flame surges and roars for about 5 seconds at a time, and a reset clears it until the next power cut...

Hello, that sum only shows a 12 litre vessel is big enough. It doesn't tell you whether yours is still holding its charge. Your summer reading is the useful clue: it held 1.3 to 1.5 with the boiler off, so it isn't losing water sitting cold. Whatever's going, goes when it heats up. So I'd still...

One of your calculator inputs is off. You put the safety valve in at 10 bar, but on a sealed heating system like yours it's 3 bar. With 3, your other figures come out at roughly 7 to 8 litres, so a 12 litre vessel is big enough on size.

Unless you're Gas Safe yourself, I'd hold off fitting a PCB. A flame that surges and roars in short bursts is a combustion problem until it's proven otherwise. I'd stop using it until a Gas Safe engineer has checked the gas pressure and combustion with an analyser, and keep a working CO alarm...

Yes, worth doing while it’s drained anyway. Charging it in 2024 with the system still full wouldn’t have given you a true reading, because the gauge just shows the water pushing back. With the water side drained and the drain open, check it and set it to 1 bar. Only change the schrader if it’s...

Yes, the Trade Tec is a heating vessel, so that’s fine on the return. It comes pre-charged at 1 bar, which suits a system like yours, so no need to touch it. You can’t have too much expansion, but bear in mind more vessel also makes a slow leak drop the gauge slower, so keep an eye on it after...

That 1.6 hot from 1.0 cold is a normal rise, so your vessel’s doing its job. It also means your overnight test may not have shown a leak at all. If you topped up to 1.5 while it was still warm, just under 1 cold is where it would settle anyway. Redo it like for like: fill with the system cold...

On a gravity system the flow comes down to how far the water level in the loft tank sits above the shower head. If that’s only a metre or so, even a low pressure mixer will feel weak. A small twin impeller pump on the hot and cold sorts it. If you go combi later the pump just comes out and the...

The void under block and beam should be ventilated, air bricks every few metres, so in winter it’s basically at outside temperature. A new run of MDPE sitting in there with no lagging is exactly what I’ve seen freeze. Insulate the whole length in the void and where it rises through the floor...

I’d not wait a week on that. Thirty seconds at every firing isn’t air working its way out, that fades after a few cycles. Something isn’t right since the pump went in. Is it like for like? Same model, same speed setting, same way round? A stronger pump, or the same one set a speed higher...