Open Vented Central Heating System - Missing Feed Expansion Tank

[kenny155]

I have an open vented central heating system.
I cannot locate a feed expansion tank in my loft, only a cold water tank.
To drain my radiators I shut off all the outlets from the cold water tank and open the tap outside the house.
Should all open vented systems have expansion tanks or is it possible for the system to be fed from the cold water tank via the hot water strorage tank.

I was draining my radiators to repair a pin hole corrosion in one of the radiators. After repairing the radiator with metal epoxy I was planning to inject a cleaner into one of the radiators, run the system for a few days then insert a some inhibitor. Should the repaired radiator be replaced or should the repair with inhibitor last for a few years.

Thanks in advance for any advice received

 

[justlead1]

Hi. You may well have a primatic cylinder, coupled with the fact that you are repairing a pin hole in rad, suggests the separating characteristics of the primatic cylinder are corrupted. The "new" water entering the CH system will corrode rads and have the pin hole effect.

 

[kenny155]

I have confirmed that I do have a primatic cylinder.
If you are not supposed to use chemicals (i currently have a cleaner in!) due to cross contamination then what do you do to stop corrosion of radiators.

I remember some time ago having problems with rusty hot water but not for over a year. How can you tell if the bubble has been corrupted

I was considering replacing my old boiler for a combi boiler. This may have made that decision easier. Should I also be replacing all of my my radiators.

Thanks for the reply

 

[justlead1]

Hi. It may well be less costly to have and indirect cylinder and F and V cistern fitted?. The rads that are not a problem will be under the sames head as now. With a combi they will have an increased at least 6 fold that of existing pressure applied.
Your money your choice, not an easy one i hasten to add. Good Luck

 

[fuzzy]

you cannot stop the corrosion mate, there in lies one of the problems. replace

 

[moony]

if you go for a combi and your having problems with pin holing now - id put my house on you having problems once theyre under pressure - save your pennies and get a complete new install mate - less worry - more efficient - and more enviromentally friendly.

 

[boilerman]

As Moony and others have said.If you change it all now it,ll save you a fortune in the future.Come into the 21st century