Help! - Noisy central heating system – not heating water well ……

[Garzie]

Have a google of any open vented diagram, the F/E pipes are always behind the circulator on the circuit and never in front, that is the cause of your air ingress issues.

Thanks again

this is rather frustrating - seems like i have inherited someone's shoddy work ....

i have had a quick google and found there are examples of both ways though

the system does not do it if on central heating central setting - only on hot water - why is that ?

and does this suggest it might be possible to run this configuration and tune the problem out somehow - maybe by fitting a restrictor or something ...?

or is the only solution re-plumbing the F/E to alternate locations ?

thanks again for your help!

 

[gmartine]

Actually the later example shows the feed pipe is nearer the rear of the circulator than the front on the circuit. Still I don't think it's a reliable example (DIY website) , needs replumbing.

 

[Garzie]

Actually the later example shows the feed pipe is nearer the rear of the circulator than the front on the circuit. Still I don't think it's a reliable example (DIY website) , needs replumbing.

OK - i am following you - thanks for the explanation - will have to have a think about how i could replumb the pipes in practice

or - if going that far anyway -

it may make more sense to redesign the system to be a closed boiler circuit system - and also create a mains pressurised hot water circuit - as hot water flow / pressure is currently too low for an effective shower upstairs - and i was going to install an additional pump for that purpose -

but installing the appropriate expansion vessels and regulators would achieve both .....

its a big job for me in my current state of health thou - and don't want to be without heating all together for long in the middle of winter - so will need to give it some thought....

 

[gmartine]

Sealing the central heating circuit should alleviate all your current problems. Cap the F/E feeds, add an expansion vessel and filling loop shouldn't cost too much or take too long to have done.

You can't pressurise an open vented HW cylinder but adding a single or twin shower pump should be straight forward enough.

Good Luck.

 

[Garzie]

You can't pressurise an open vented HW cylinder but adding a single or twin shower pump should be straight forward enough.

thanks

i had wondered about that - my guess is the system was installed around 12 years ago - probably just before pressurised systems became the norm - there are no pressure rating markings on the HW tank - so i guess it is the non-pressurised type
shame

will go with the pumped shower solution - think i just about have room to install this and a pressure vessel in the airing cupboard

ref the expansion vessel for the boiler circuit - is there a rule of thumb i should follow for the size i should use

i guess its based on volume - the system is smallish - 5 radiators and the HW tank coil - smallish 3 bed house
2x 6ft double layer radiators
1x 3ft double layer radiators
1x 6ft single layer radiator
1x 3ft single layer radiator

any other gotcha's i should look out for

thanks again !

 

[gmartine]

If it's a 60's house chances are you don't have the water pressure and flow rate to be able to utilise an unvented cylinder anyway.

An EV is usually based on 10% system volume'ish so an 8 litre EV would do for a small system.

 

[Garzie]

have ordered a 12litre EV and install kit to err on the safe side - plan to install it in the AC above the HW tank - directly into the lines that currently go up the wall into the loft to the expansion tank.

was very reasonable - here -

Altecnic - ERES 12 Litre Heating Expansion Vessel & Sealed System Kit ER-12LTVESS

Altecnic - ERES 12 Litre Heating Expansion Vessel & Sealed System Kit ER-12LTVESS

www.unventedcomponentseurope.com

do i need anything else ?

anything i should watch out for ?

 

[gmartine]

What lines, your F/E pipes? The EV ideally needs to go on the return side of your system.

https://www.altecnic.co.uk/wp/wp-content/uploads/resource-files/Pressure_Vessel_Instructions_IOM.pdf

 

[Garzie]

yep - the F/E pipes

i see the instructions say preferably on the return side - but doesn't say MUST - so i m hoping that is not essential

as i understand it as long as the system volume is able to expand unhindered into the vessel - then it will work correctly - and since no air can get sucked in via the vessel - that should solve the air issue

no?

 

[gmartine]

Here's some instructions that say "must" be on the return and no obstruction between it and the system so I wouldn't locate it before the three port as you propose. Also the EV postioned there is far more likely to fail because of the higher water temp.

https://www.vip-ltd.co.uk/Expansion/Expansion_Vessels/22_0330/Cal-Pro%20Expansion%20Vessel%20Instructions.pdf