Is there a future for vented systems?

[sirocosm]

That's to do with HW from the taps and shower.
In #23 you said "My current vented system's F&E pipe is way less than that (2.5m), and the system is full of sludge, and one of the radiators has rusted through. It is around 25 years old", which I assume is the primary circuit. Is the 2.5m a pipe length? Sounds like it needs a good clean, Powerflush or something, and replace the leaking rad. Then add the correct dose of inhibitor, and you should be OK for years. Of course you can convert it to a sealed system if you want, but I wouldn't.

I plan to replace current my vented system with a thermal store, preferably sealed.

 

[sirocosm]

Plenty of open vented cylinders and open vented boilers here in beautiful blighty,when either wears out they can be replaced with open vented cylinders or boilers without the need to charge the customer quiet a lot of extra money for converting etc.

why make the job more expensive for the customer ?

The 2 separate water taps,its down to preventing potable water contamination

thermal stores have been mentioned but you have Heath Robinson ideas about them,hey stick to what you know Not what google tells you

Kind of thought so

I guess unvented thermal stores are what I "know" best. I installed one in my previous house and it worked fabulously. There was no house stat, all the rads were controlled by TRVs. This meant they were always "on" and there was no cycling when the boiler cut in and out. It was very comfortable. Mains pressure water too.

 

[fixitflav]

I plan to replace current my vented system with a thermal store, preferably sealed.

With that you still have the options of keeping the F/E tank on the primary side, or replacing it (if you insist ) with an expansion vessel. But the system still needs cleaning, and the rad replaced.

 

[sirocosm]

With that you still have the options of keeping the F/E tank on the primary side, or replacing it (if you insist ) with an expansion vessel. But the system still needs cleaning, and the rad replaced.

I am going to put the store in the garage, and eventually relocate the boiler, so most of that piping will be changed. Many of the rads are plumbed in with 10mm snaked through the floor. I am going to toss all that and the rads and replace them with cast iron reproductions, or salvage if I can find them cheap. I really like the cast iron rads. I will replace all the rad piping with 15mm soldered copper, 2 or so rads per leg to the 22mm main.

I am still torn on vented/unvented. I would go sealed, but in the UK this requires G3, and I am struggling to find a G3 to install just the tank with me doing the rest. I have read that G3 DIY is complicated and expensive. So I guess another reason for vented systems in the UK is less regulation.

 

[fixitflav]

I am going to put the store in the garage, and eventually relocate the boiler, so most of that piping will be changed. Many of the rads are plumbed in with 10mm snaked through the floor. I am going to toss all that and the rads and replace them with cast iron reproductions, or salvage if I can find them cheap. I really like the cast iron rads. I will replace all the rad piping with 15mm soldered copper, 2 or so rads per leg to the 22mm main.

I am still torn on vented/unvented. I would go sealed, but in the UK this requires G3, and I am struggling to find a G3 to install just the tank with me doing the rest. I have read that G3 DIY is complicated and expensive. So I guess another reason for vented systems in the UK is less regulation.

I thought G3 only applied to unvented HW cylinders, not installing an expansion vessel on the primary circuit to replace an F/E tank. No doubt somebody will soon tell me if that's wrong.

 

[sirocosm]

I thought G3 only applied to unvented HW cylinders, not installing an expansion vessel on the primary circuit to replace an F/E tank. No doubt somebody will soon tell me if that's wrong.

I think thermal stores are a grey area. Most agree any sealed cylinder of heated water, even if it low pressure (PRV at 2 bar), then G3 is probably required.

 

[Madrab]

Thermal stores are in effect low pressure open vented cylinders, so no G3/UVHW qual req but they are prone to sluging up if not kept clean

 

[sirocosm]

Thermal stores are in effect low pressure open vented cylinders, so no G3/UVHW qual req

Not if they are sealed. I would prefer mine to be sealed, if possible, to avoid corrosion.

 

[Madrab]

Not sure if they can be sealed tbh .... the norm for thermal store in the UK is that they are vented & have either a small f&e tank on top or above. It's of their their main selling points against unvented cylinders. Yet to see an unvented thermal store and I'm a G3 installer but hey, never say never. They're always coming out with new stuff.

 

[ReJect]

You can get thermal stores that are indirectly heated and have a water content that is a ‘dead’ water store which allows transfer of heat from the heating system coil to the hot water heat exchanger.
That means the water in the cylinder is treated with inhibitor, but is not part of the heating system and will not sludge up.

Directly heated thermal stores are different and ideal for solid fuel boiler systems, but can sludge up and act as a sludge bucket unfortunately and will corrode

 

[sirocosm]

Not sure if they can be sealed tbh .... the norm for thermal store in the UK is that they are vented & have either a small f&e tank on top or above. It's of their their main selling points against unvented cylinders. Yet to see an unvented thermal store and I'm a G3 installer but hey, never say never. They're always coming out with new stuff.

I installed one of these in my previous house:
http://plumbingsupplies24.co.uk/hygienic-buffer-storage-tank-vertical/

I ran it at 1.5bar and it had a PRV at 2 bar. It worked great. It is a mild steel tank, so it must be sealed or it will rot. It has a massive 4.1 sq m corrugated stainless steel coil for DHW.

Now if only I could find a G3 in Norwich to install one for me.

 

[ReJect]

G3 is not generally a difficult qualification to achieve and lots of plumbers should have it.