Cleaning system with direct feed hot water tank

[Ratty]

I've got an old heating system in my house, Baxi back boiler and 8 rads. Some of the rads have been getting warm at the top but cold at the bottom. I took one out and flushed it through. It took nearly an hour with a hose before I could get a clean flow! I though I would run some Sentinel X400 through the system but I've hit a problem. After draining the system and re-filling I found the hot water tank emptied when I drained and on refilling the hot water is brown. I'm assuming from that that the tank is a direct feed tank and not an indirect. I assume then that the only way to clean the heating system properly will be to swap to an indirect heat tank and then flush the whole system? I don't mind changing the tank as the current one isn't insulated apart from one of those 'blanket' type things that strap around the tank.

 

[chris watkins]

The existing cylinder is most likely a Primatic (single feed) one, is there an F&E cistern in the loft or top of a cupboard ? As you say, best to get it replaced but take care if your current system is gravity circulation.
Flush all rads first & replace cylinder before using cleaners.

 

[Ratty]

Yes, there is a cold water tank above it. Not sure if it's a single feed as you say though. I'm away tomorrow so I'll take a look on Thursday. Going by the pipes coming out of the boiler, 4, 2 x 22mm and 2 smaller (one pumped for rads) I assume it's got the two 22mm pipes feeding it? If I change the hot water tank which is best, copper or a stainless steel tank? Looking at the B&Q Tradepoint catalogue stainless is slightly cheaper but is the saving worth it?

 

[GasmanxxxR1]

It'll be a primatic cylinder as previously stated, change for an indirect on and add a new F&E tank for your heating system

 

[Ratty]

If I fit a new F&E tank for the heating system what would be the minimum size needed? There's no room in the cupboard with the current tank so I would have to put it in the attic and the hatch is pretty small. I would imagine it wouldn't need to be big as it's only to keep the small heating system fed.

 

[GasmanxxxR1]

4 gallon one is the norm

 

[Ratty]

4 gallon one is the norm

Thanks.

 

[chris watkins]

You are going to need a plumber for this one I am afraid there are just too many pit falls, apart from the fact that to replace a cylinder the person carrying out the work should hold the Part G ticket. A lot of the cylinders sold can not be used with gravity primaries, it may be time to upgrade to fully pumped.