Ideas for new heating/HW.

[Neil Jones]

In the middle of summer just before you are off on holiday and 10 minutes before the arrival of the boiler engineer you had previously arranged to service the thing anyway?

[Christian McArdle]

Indeed. Horrible things. Change it at your earliest convenience. Luckily, this will be soon, due to the banning of inhibitor, unless you like a little inhibitor every time you have a bath.

I'd start again, although don't immediately decide to throw away the radiators, particularly if they're pretty column types. These are extremely expensive and likely to be in reasonable internal condition as they were built like brick outhouses. The only advantage of replacing a old column radiator in good condition is that the modern replacements will be much smaller. If you do decide to rip out any column types, sell them on eBay or to a dealer.

No, but it can save you a fortune. When the boiler went in my last house, it meant I could sit pretty and find an excellent quote (i.e. 500 quid for fitting) rather than ringing BG in a panic and paying 2500.

Christian.

[IMM]

Nonsense! see my post on this.

They are not horrible at all.

Nonsense again

[Christian McArdle]

Can you honestly recommend Primatic (Indirect Self Priming) cylinders?

A simple "yes" would suffice, and then I can call the men in white coats with the padded van.

Christian.

[IMM]

They are still made by many makers. 25 years ago many said they would go in a few years. They cut down on installation costs. Fitted right they work well. I personally would not recommend one, but if one is in and it work OK, leave it. They are superb in flats where there is a communal header tank for water. Just fit one of these and no space taken by a F&E tank. They are the perfect choice for some situations.

[Christian McArdle]

If you really wanted gravity fed water in the same footprint, then a combination cylinder and sealed/pressurised primary would be vastly superior. The chances of contamination of the hot water system by inhibitor is real, as is the chances of dilution of it over time.

Christian.

[PoP]

Could someone please explain what a primatic cylinder is as I am not familiar with the term?

I presume it might be a boiler which delivers its load direct to the taps rather than heating a coil in a hot water cylinder thru a sealed circuit, but perhaps I'm looking in the wrong place for an explanation.

PoP

[Tim Downie]

See

all seem pretty unanimous on the point.

Tim

[IMM]

Read again. Special inhibitor for primatics is used.

[IMM]

A primatic cylinder does away with the CH F&E tank, cutting out the time and pipework involved. The CH system is filled via the cylinder. Once filled two air bubbles keep the CH water and fresh water in the cylinder separate. You need to use special inhibitor with it.

[Nick Brooks]

Please tell ne the name of the "special inhibitor" and where I can get some

I am worried because the above links said the following:-

"If you have a Primatic cylinder and you must NOT use and Fernox product."

"Primatic - system additives must not be used with this type of cylinder as this will come out through the hot taps"

"If you only have one supply cistern, or your cylinder is marked Primatic, then you should not use treatment chemicals."

thanks

Nick Brooks

[IMM]

It is many years since I topped up a primatic. We used special inhibitor. can't remember the name. The makers will tell you the type to put in.

[Christian McArdle]

It's an abomination of a bodge that uses the DHW feed to fill the central heating, causing occassional intermingling of the water, preventing the use of chemicals. Almost all boiler manufacturers specifically forbid their use, as they promote corrosion in the system.

Christian.

[Nick Brooks]

Good

We used special inhibitor.

[IMM]

There should be no mingling of water in normal operation.

Special inhibitor is available for them

They do not like them as they operate on gravity hot water, although I have seen one on a pump and it worked OK. Few boilers can operate this way these days. They do not promote corrosion. They are better suited to soft water areas though.

[Tim Downie]

Okay, I've read again. Still can't see any suggestion of what to use.

Care to share your knowledge?

Tim

[IMM]

Long time ago, but a special primatic inhibitor was used. You put it in a big rad once the system was filled. Drain the rad and inject. The makers of the cylinders would help.

[Tim Downie]

I see, you don't actually know and you're quoting practice from a long time ago.

I'm sure anyone with a primatic cylinder with find that utterly convincing.

Tim

[IMM]

I do know. I told you.

Primatics have been around for yonks.

convincing.

They should do, as I know more than them.

[Tim Downie]

No you didn't. You claimed knowledge that you can't substantiate and is flatly contradicted by additive manufacturers.

Tim

Tim