Primatic water system anyone???

laxeylady

Hi we are in the process of replacing our Aga (for another!), which led to us having to weigh up our hot water system. I am ashamed to say that we had no clue how the aga provided us with gallons of hot water and now that we know that we have a single feed indirect system (primatic?) we are faced with a problem. We bought a pumped shower in last years sales and from what we can gather from the internet they should not be installed on our kind of system. Has anyone any experience of primatic systems? The aga water in the system is clean (no rust or inhibitors etc) so if the shower disturbs the air bubble will the system 'reboot' once the shower stops running? Will we need to sell the shower? Replace the tank? Cheers for any advice.

Canucklehead

Hi.

Primatic not recommended for pumped showers.

You also need 220 litres of stored cold water for a pumped shower.

Consult Aga for the details such as the need for 190 litres of hot water cylinder capacity.

GSR

laxeylady

We have already replaced the cold tank in readiness for the shower, and the hot tank is also big enough for its requirements. We just never understood what was going on inside the hot water tank! I suggested to hubby that we installed another hot tank to run the shower only (which would be heated by immersion) but he's not keen on that idea.

denwyn

laxeylady wrote: »

We have already replaced the cold tank in readiness for the shower, and the hot tank is also big enough for its requirements. We just never understood what was going on inside the hot water tank! I suggested to hubby that we installed another hot tank to run the shower only (which would be heated by immersion) but he's not keen on that idea.

Sorry but a primatic hot water tank will not work with a power shower,if you do try it you wll end up with brown hot water when it mixes with the water in your heating system. Primatic tanks are fairly old now, and wer not really designed for any form of pumped system,either pumped from the boiler or out to the taps.I have not seen them about much for a long time, best to change the hot water cylinder to an indirect tank, fairy straightforward job,onlt extra is a small expansion tank (cold water tank) to fill heating syatem. Much better system than a primatic.

Canucklehead

denwyn wrote: »

Sorry but a primatic hot water tank will not work with a power shower,if you do try it you wll end up with brown hot water when it mixes with the water in your heating system. Primatic tanks are fairly old now, and wer not really designed for any form of pumped system,either pumped from the boiler or out to the taps.I have not seen them about much for a long time, best to change the hot water cylinder to an indirect tank, fairy straightforward job,onlt extra is a small expansion tank (cold water tank) to fill heating syatem. Much better system than a primatic.

Just like in the link then.

In fact they are suitable for fully pumped circuits, and are available.

OP, the one in the link is 'only' 152 litres. Unless you have a different make @ 190 litres you don't have the recommended capacity.

Make sure, if it's replaced, to get one that is for gravity circulation, otherwise it will be slow to heat.


GSR.

laxeylady

So we have a shower we can't use - it'll have to go in the paper. But what do we do now? We have an enclosure to use and wanted the most powerful shower possible. We don't want to mess with the hot tank - it is working well. What are our options? Any advice gratefully received.

George_Bray

denwyn wrote: »

Sorry but a primatic hot water tank will not work with a power shower,if you do try it you wll end up with brown hot water when it mixes with the water in your heating system. Primatic tanks are fairly old now, and wer not really designed for any form of pumped system,either pumped from the boiler or out to the taps.I have not seen them about much for a long time, best to change the hot water cylinder to an indirect tank, fairy straightforward job,onlt extra is a small expansion tank (cold water tank) to fill heating syatem. Much better system than a primatic.

I disagree. There was a single feed Primatic water cylinder in my house from the mid 1980s until a few days ago, when I made a big mistake and removed it, to fit a simple indirect tank, like you suggest. I now think it's a retrograde step and wish I'd kept my trusty Primatic cyclinder. It was brilliant and never failed. Whoever designed the single feed Primatic system was a genius. In the mid 1990s, unaware of advice not to fit a power shower, that's exactly what I did. The shower worked perfectly and never caused any problems.

Why did I remove the Primatic cyclinder? I assumed it must be full up with calcium after almost 30 years and somehow worn out. A basic indirect cylinder I opened some time ago had 14kg of calcium inside. but when i opened up the Primatic cylinder, there was almost no trace of calcium and I'm sure the cylinder was almost as good as new. It's amazing but I read that it's one of the claimed advantages of the Primatic cylinders. So if you have a Primatic cylinder, my advice is to keep it. I wish I had. I fear plumbers and heating people use the fact they are 'old' as an excuse for carrying out unnecessary work.



I ripped out the heating element inside to take a closer look. The inner cylinder is double walled and I think the water circulated from the boiler, fills the space in between, as well as a large volume below the dome. There was no sign of calcium in there, either, despite the house being in a hard water area. The single feed works as follows - when the water in the main part of the cylinder gets almost to the top it flows up the vertical pipe and then down into the indirect chamber. Somehow an air bubble is formed and keeps the two parts of the system separate. Brilliant.

southcoastrgi

That's it accuse the trades of ripping people off by doing un-necessary work

"I assumed it must be full up with calcium after almost 30 years and somehow worn out."

so what's your excuse then ?

pot & kettle spring to mind

George_Bray

southcoastrgi wrote: »

"I assumed it must be full up with calcium after almost 30 years and somehow worn out."
so what's your excuse then ?

As I said: "A basic indirect cylinder I opened some time ago had 14kg of calcium inside."

Also, for once, just once, I thought there might be a grain of truth in the claims of traders around here, who have replaced many similar cylinders, in neighbours' houses, claiming they will be worn out and full of calcium. I now realise such claims are probably bogus and just a way of selling unnecessary work.

The problem with a money saving site like this, is allowing traders to come on and rubbish consumer warnings like mine.