Feed and Vent fun :DDDDD

[Best]

If the system had no push fit, then I would try to convince the customer the benefits of a sealed heating system

 

[ShaunCorbs]

If the system had no push fit, then I would try to convince the customer the benefits of a sealed heating system

Already tried won't have it (think it's been diy soldered)

 

[sammathias]

If the system had no push fit, then I would try to convince the customer the benefits of a sealed heating system

I'd like to think pushfit can with Stand 1bar!! Although I dispise the stuff.

 

[Best]

I'd like to think pushfit can with Stand 1bar!! Although I dispise the stuff.

Only reason I mentioned push fit as a risk is I hear of some coming apart.
One customer has the expansion vessel and filling loop in attic and kept the pressure to nearly zero because he said a push fit fitting below his hall floor had once come off. Worry is he had since put hardwood flooring over the hall.

 

[ShaunCorbs]

Normally no inserts used

 

[fixitflav]

But I wouldn’t be sure if it would pump over

Why would it pump over, if the headloss between open vent and cold feed is < height of vent loop above F/E tank TWL? Which it must be anyway to avoid over-pumping, however the system is arranged.

 

[fixitflav]

Technically it is before the pump

And he won't seal it due to him thinking it won't take the pressure

If the F/E tank and pipework are existing, why go to the expense of changing to an expansion vessel? You would still need to decide where to connect it (ideally between boiler and pump IMO)

 

[Best]

Difficult to say Shaun what you should do. If you combined the feed and vent I think would be wrong as I find that causes systems to corrode.
Pity you can’t install new feed & exp tank and new vent and feed pipework at boiler end.
One solution would be neutral point installed where the feed and vent could then come off it. But am sure you don’t want to do that.
I am actually having the same problem trying to decide how I convert a gravity hot water/pumped rads to all pumped on a very old system, without pump over or corrosion.

 

[Best]

Why would it pump over, if the headloss between open vent and cold feed is < height of vent loop above F/E tank TWL? Which it must be anyway to avoid over-pumping, however the system is arranged.

If you are right, then that is his answer just to go with vent and feed ahead of pump. I would wonder if most of zones are closed, would it still be ok.
Where possible I would seal systems because the cost is very little (if vessel size required is not large).

 

[oilmark]

Open vented system must have vent from flow on boiler before any other connection.