Only one header tank

[edalerichard]

While fitting a new radiator at friends house disovered there is only one tank. So obviously any inhibitor added to the system could be drawn off bit by bit via expansion into the hot water cylnder.Should I either leave the system un-dosed (as it always has been) fit a separate expansion tank ,theres easy access and plenty of room. Bearing in mind the crud in most headers its unlikely anyone would drink from a hot tap...but I think a mixer of crud and inhibitor would be Very bad thing indeed. Ta, everyone

[Chris Bacon]

There should be absolutely no connection between the CH and the other side of things. Are you sure of your facts?

[edalerichard]

Certain, never seen a set up like this. Another curio is the vent pipe from the boiler is only 15 mm.

[Mark]

You may have a primatic cylinder, in which case do NOT put any inhibitor in because it could get into the DHW.

See

[mike]

[e-mail] wrote in news: [e-mail]:

Sounds like a Primatic cylinder, where the circulating boiler output is topped up from the clean water in the tank.

Dosing would be a very bad idea, replacing with a conventional cylinder and Feed/expansion header prolly would; often though these were used because of shortage of room, (or parsimony)

mike

[Dave Fawthrop]

| [e-mail] wrote: |> While fitting a new radiator at friends house disovered there is |> only one tank. So obviously any inhibitor added to the system could be |> drawn off bit by bit via expansion into the hot water cylnder.Should |> I either leave the system un-dosed (as it always has been) fit a |> separate expansion tank ,theres easy access and plenty of room. Bearing |> in mind the crud in most headers its unlikely anyone would drink from a |> hot tap...but I think a mixer of crud and inhibitor would be Very |> bad thing indeed. Ta, everyone | |There should be absolutely no connection between the CH and |the other side of things. Are you sure of your facts?

Untrue.

In the old old days people used primatic systems

which had only one tank. The link indicates that they are still available and legal. The HW and CH circuits were kept separate by gravity. But CH water could ?leak? to the HW circuit, so I would not use inhibitor.

[Doctor Drivel]

Primatic cylinders were expensive. Although before poly F&E tanks and they were zinc coated steel, it may have made some sense in equipment purchase. It was just quicker to install, probably saving a little on labour, if anything. I could never see the reason for them once poly F&E tanks came about, and they are still sold.

Some makers say you can dose the CH, but only directly into a rad and the inhibitor has to similar to X-100 or the harsher Fernox.

[Doctor Drivel]

By two air bubbles, in fact.

[Chris Bacon]

Even with a primatic system there should be no connection between the CH and the other side of things, so you're wrong - unless you are claiming that mixing of CH water with the rest is normal.

[Doctor Drivel]

He is more right that you that is clear. Only two air bubbles separate the CH and secondary fresh water.

[Chris Bacon]

The systems keep both water systems separate. I said that. DF said that. Now you have also said that. Thank you for agreeing with me as well!

[mike]

"Doctor Drivel" wrote in news:449a753e$0$11186$ [e-mail]:

That brings back memories - I grew up with a steel squarish one, about

3x3x1ft deep, that fitted neatly under the airing cupboard.

Some time when I was away defending queen and country, it got replaced by a cylinder that didn't fit in the space.

Prolly some mad scam/scheme by B-I-L and his family; I never enquired about those things

mike

[Dave Fawthrop]

|Dave Fawthrop wrote: |> Chris Bacon wrote: |> | [e-mail] wrote: |> |> While fitting a new radiator at friends house disovered there is |> |> only one tank. So obviously any inhibitor added to the system could be |> |> drawn off bit by bit via expansion into the hot water cylnder.Should |> |> I either leave the system un-dosed (as it always has been) fit a |> |> separate expansion tank ,theres easy access and plenty of room. Bearing |> |> in mind the crud in most headers its unlikely anyone would drink from a |> |> hot tap...but I think a mixer of crud and inhibitor would be Very |> |> bad thing indeed. Ta, everyone |> | |> |There should be absolutely no connection between the CH and |> |the other side of things. Are you sure of your facts? |> |> Untrue. |> |> In the old old days people used primatic systems |>

which had only |> one tank. The link indicates that they are still available and legal. The |> HW and CH circuits were kept separate by gravity. | |Even with a primatic system there should be no connection |between the CH and the other side of things, so you're |wrong - unless you are claiming that mixing of CH water |with the rest is normal.

The operative word is *should*, I would not trust it.

[Doctor Drivel]

An Elson, still made today.

Typical. The local idiot plumber looks at it, can't figure it out, or not available at the local, plumbers shop and fits a cylinder. Elsons are great. They are square and save space. They are mainly sell to developers for new houses.

I have seen this with thermal stores too. In one instance the blending valve had gone, the whole estate was fitted from new with them. All the idiot plumber had to do was phone up Range and they would send one overnight for around £25-35. The loony didn't understand thermal stores. He convinced the householder to fit a tank in the loft, a cylinder and a power shower pump at great expense, and athe shower was nowheer near what teh mains gave. I would have taken the bastard to court. Apparently you can, and will win in these situations. If he doesn't know what a thermal store is he shouldn't be trading.

[Richard Conway]

Better get yourself a good lawyer then.

[Doctor Drivel]

Russ, where you the cowboy that did it then?

[Chris Bacon]

AOL. We're sort of disagreeing about wording, I think. I would get rid of a Primatic system if I could.

[Dave Fawthrop]

|Dave Fawthrop wrote: |> Chris Bacon wrote: |> |Even with a primatic system there should be no connection |> |between the CH and the other side of things |> |> The operative word is *should*, I would not trust it. | |AOL. We're sort of disagreeing about wording, I think. I |would get rid of a Primatic system if I could.

OP said it was not his, so he should advise his friend to replace it.

[Mark]

The bubble(s) can collapse letting both primary and secondary circuits mix. I would not trust one either.

Mark

[Mark]

Another drawback of a Primatic cylinder is that you have to use gravity feed for the HW primary.

Mark