My Install - some questions!

[Duncan62]

Hello all, thanks to the fantastic BH I've had a go at my UFH / DHW install. 

 

Be nice (please!) but tell me if it's wrong!

 

Q1: how do I go about filling the system? Do I use the full and flush valve, hose pipe? Or pipe in a hep2o from mains?

 

Q2: I have a huge plastic container of glycol for anti freeze. How do I get that in the pipes? How do I get the correct ratio?

 

Observations:

DHW Will loop to UVC, but currently loops back to exit so I can get the system running as I need to commission the slab with heat cycle.

[Nickfromwales]

31 minutes ago, Duncan62 said:

Hello all, thanks to the fantastic BH I've had a go at my UFH / DHW install. 

 

Be nice (please!) but tell me if it's wrong!

 

Q1: how do I go about filling the system? Do I use the full and flush valve, hose pipe? Or pipe in a hep2o from mains?

 

Q2: I have a huge plastic container of glycol for anti freeze. How do I get that in the pipes? How do I get the correct ratio?

 

Observations:

DHW Will loop to UVC, but currently loops back to exit so I can get the system running as I need to commission the slab with heat cycle.

Nice work. 
 

You need to tee into the hard cold mains feed and connect this part of the “filling loop”.   

 

 

Don’t use softened water.

 

That filling loop is how you fill the heating system. 
 

Fill and test for leaks without treating it, check for the next 48/72 hrs to be certain you’re kosher, and only then do you put the glycol in. 

[JohnMo]

30 minutes ago, Duncan62 said:

freeze. How do I get that in the pipes? How do I get the correct ratio

Best ratio - is no glycol at all - why are you adding. It just degrades system performance. If you really want freeze protection for warranty, buy two anti freeze valves. But ones that respond to water temperatures not outside temperature.

 

The flexible hose by the expansion vessel, should tee into the cold water main and act as filling loop.

 

But you UFH loops will need filling and air got out of the system - you would use a hose on the UFH manifold for that, one loop at a time.

 

Not seeing many useful auto bleed points

[Nickfromwales]

These 2 are supposed to be the other way around, so you can clean / service / replace the double check valve by turning the stopcock off. 
 

Should be a quick swap with just a spanner. 
 

[Nickfromwales]

3 minutes ago, JohnMo said:

Best ratio - is no glycol at all

Not if the ASHP manufacturer states that it is mandatory, in the MI’s. 

 

Bottle vent on the manifold seems to be suffice, as it looks to be the highest point there. 
 

The feeds to upstairs should vent through the heating up there, vent on manifold #2 or rads. 

[JohnMo]

3 minutes ago, Nickfromwales said:

Not if the ASHP manufacturer states that it is mandatory, in the MI’s. 

True, but do any modern ASHPs say glycol is the only option?

[Nickfromwales]

Just now, JohnMo said:

True, but do any modern ASHPs say glycol is the only option?

Whether we like it, or dislike it, agree or disagree, the manufacturers installation guide is the bible. 

 

Some dont stipulate, some do, some are happy with anti-freeze valves, which I opted for on the last ones where I had 'free reign', but we should make the OP aware that they need to check if they are OK to deviate.

 

Me personally, I hate the thought of glycol. No need for it, but there is always the power cut in the arse of winter to consider as worst-case.