gravity circulation

[jackso]

Hi Guys
New to the forum, I could do with some info. Have been to a job in last couple of weeks where the customer has had a new indirect cylinder fitted to a gravity hw and pumped heating system ( abit naughty I know). Customer says that when hw is on in the afternoon it boils and bangs but everytime i,ve been it runs fine, I,ve boiled it etc and to me it circulates great. The boiler is a free standing potterton kingfisher 60cf. It did have a primatic cylinder in which developed a leak. The pipework looks fine, vent off the flow circ and feed into the return, only thing i can think of is the last 10 inches of the circs to the cylinder of pipework are 22mm and not 28mm, do new indirect cylinders work with gravity?

 

[Puddle]

As said,should not have fitted without upgrading to meet energy efficiency requirements however the 22mm should not make a great deal of difference placed in last section
If boiler state ok,could be sticking,would look to something else like a ball valve closing causing vibration,maybe she is putting 2 and 2 together as so many customers do after a job and coming up with 5 as problem not related,is system drained b/valve washers could have dried out ect

imho

 

[jackso]

Thanks puddle, its a tough one to figure out

 

[stevetheplumber]

As said,should not have fitted without upgrading to meet energy efficiency requirements however the 22mm should not make a great deal of difference placed in last section
If boiler state ok,could be sticking,would look to something else like a ball valve closing causing vibration,maybe she is putting 2 and 2 together as so many customers do after a job and coming up with 5 as problem not related,is system drained b/valve washers could have dried out ect

imho

theres no obligation to upgrade the system when changing a cylinder only when changing the boiler

 

[diesel_ltd]

alright mate,

did you read the data sticker on the side of the cylinder, it will tell you if the new cylinder and be fitted to a gavity system. Soom new indirect cylinders and only for a fully pumped system.

diesel

 

[Puddle]

Well I would say you are under an obligation to upgrade by not a regulation as far as a straight swop goes

However it could be argued this is not a like for like swop anyway

You are replacing a primatic cylinder for a coiled cylinder ,a new instalation,so should be upgraded under regulations

 

[diesel_ltd]

sorry about the spelling its been a long day (BAXI BARCELONA!!!)

 

[jackso]

Thanks guys, this is going to be one of those jobs

 

[diesel_ltd]

one of those jobs you wish you hadn't started good luck mate keep us posted

 

[Ebenezor]

Jackso, I doubt if the new indirect cylinder is suitable for a Gravity Primary circuit.
In the old day such "Indirect cylinders" had at least an 1" coil.
Having said that...You have got a circuit and water is getting hot.
So your problem is the Cylinder boiling?
Without any controls fitted to the DHW, the only temperature control is the Boiler stat, if this is set on 60c...How can it boil? is it faulty ?
Is it venting into the heating F & E tank?
BTW....do you still get a Gravity circuit when the pump runs for the heating ?

Regards
Ebe

 

[jackso]

Thats part of the problem ebe it hasn,t done when i,ve been there but i am starting to think you could be right with the cylinder coil once it gets up to a certain temp