heating system design

[joe1234]

im installing a new system .The system boiler will be on the ground floor and the hot cylinder in the loft can i fit two ,two zone motorised valves next to the boiler to feed heating and hot water or next to the cylinder so the flow for the heating goes to the loft and then back down to the ground floor any thoughts or suggestions thanks Joe

 

[gassafeengineer]

are you RGI

 

[45yearsagasman]

I doubt it as a system boiler normally contains the zone valves needed to control most systems.

 

[Biggles..]

Ffs a system boiler doesn't contain any zone valves only the pump, expansion vessel and relief enabling your system to be sealed.unless you have a very specific make/model which would then be a 4pipe system boiler.

 

[bobthebender]

Ignore the three posts above as it's obvious that they don't know what they are talking about and have never fitted a system boiler and you might not need an RGI....no one said gas.

Put in two zone valves on the flow where you can and don't forget a bypass before the valves.It would be neater in the loft next to the cylinder but that depends on layout/property.

 

[Nige F]

RGI.....Ffs.... what does it all mean

 

[Foobix]

If there room,fit the zone valves by the boiler.Less work and easier for maintenance purposes.

 

[Biggles..]

Ffs a system boiler doesn't contain any zone valves only the pump, expansion vessel and relief enabling your system to be sealed.unless you have a very specific make/model which would then be a 4pipe system boiler.

Come on then bender,what in there would let you believe I've never fitted a system boiler.

 

[mysteryman]

RGI is a Registered Gas Installer; ffs is an abbreviation used in this instance by an extremely rude and ill-mannered person.

The best System boilers do have an on-board diverter valve. But if you use external valves and make it a three port valve, you do not then need a bypass, as one port will always be open.

 

[Biggles..]

Rude.... yep,because when people go on about 45years and expert then surely the basics shouldn't be that difficult for them. There are probably a hand full of system boilers with inbuilt divertors compared to 100ish that don't.

You've not managed to recommend a viessman in your thread yet,not like you.

 

[Agile]

Whilst you could use two two port valves, its cheaper and just as good to use a three port valve which then does not need any autobypass.

If you put a notor valve by the cylinder then you would need two cables from the boiler.

Unless you were very competent with pipework design, I would recommend that you run both flow and return dedicated to the cylinder and do not try to share the return.

Who is installing the boiler?

Tony

 

[Andygasman2010]

im installing a new system .The system boiler will be on the ground floor and the hot cylinder in the loft can i fit two ,two zone motorised valves next to the boiler to feed heating and hot water or next to the cylinder so the flow for the heating goes to the loft and then back down to the ground floor any thoughts or suggestions thanks Joe

What boiler are you having fitted? By "system boiler" I assume you mean it contains the pump, expansion vessel and pressure relief. This is the most common set-up in a system boiler. There's no advantage in getting the lesser common type that contains motorised valves unless you want to add weather compensation.

Either two zone valves or one three port valve will do just fine, i'd probs go for a three port mid-pos valve depending how big the system was.

Assuming it's going to be a sealed system it doesn't matter too much where you put the plan but i'd say put it near the boiler and run completely seperate flow/return pipes up to the cylinder and make sure the cylinder return is the last one before the boiler.

 

[joe1234]

Thanks for your replys. Im not doing the gas a RGI engineer is and checking the tank in the loft.The boileris a potterton gold system he and has a internal bypass so was going to use two two zone valves next to boiler as in a cupboard so room for valves.Will bring tank return down to boiler as mentioned all pipe work will be 22mm. what is the advange of having a dedicated return for the tank and not shared.
Thanks for the help Joe

 

[Foobix]

Even thou the boiler has an internal by pass,its good practise to fit one externally,especially if the rads have TRV's fitted.

 

[joe1234]

Even thou the boiler has an internal by pass,its good practise to fit one externally,especially if the rads have TRV's fitted.

yes rads will have Trvs but will have towel rail in bathroom with no TRVs but no good if valves stick so how close can the bypass be to boiler. thanks Joe ps any thoughts on thededicated return for tank