Update: Magnetic central heating filter worth it or just flush system with Sentinel X800?

[Aquaheat]

On a side note, how often do you lot come across direct central heating systems these days, they must be pretty rare. I am talking about the type where the hot water that is drawn of from the HW tank is the same water as circulated and heated by the boiler? Did these systems ever have radiators connected up to them?, Limescale must have been a real issue with the water constantly being replaced?

You're on about a primatic cylinder. Yes they are very rare now and we should be really pushing to have them removed whenever we come across one. Not because we want to sell stuff but because they really aren't healthy! Have been doing this for nigh on 20 years and come across about 10 of them. This was in the B'ham area though and mostly the black country and TBH they weren't that that badly scaled but we had softish water there. Ooop here they'd have probably lasted about a month.

Jon

 

[eveares]

You're on about a primatic cylinder.

Just remember seeing a diagram when I was a child in a old DIY book that my parents had from the 80's, IIRC there was two diagrams of central heating systems featuring a gravity fed boiler, pump, radiators, etc...; a indirect one with heating coils in the HW tank and a direct one without the heating coils in the HW tank.

Now I have looked on line at "primatic cylinders" on line and some appear to feature a couple of small air pocket in them, don't remember that from the old DIY book. Am I correct in that the hot water drawn of from the HW tank was the same water as circulated and heated by the boiler; if so how was lime scale prevented in hard water areas?

Edit: Just seen this; I also guess non pumped HW cylinders are also rather rare today as well. Remember learning about in the early days, only the radiators were pumped and the HW tank just relied on natural convection currents to carry the water from and to the boiler.

 

[Aquaheat]

No the DHW and the heating water were seperated by a baffle inside the cylinder. When first filled it created an air pocket that kept the two sides seperate. The issue was that over time this pocket would diminish through being absorbed into the water etc and would then allow the two sides to mix and you would then be washing with your heating system water.

A better image that shows it a little clearer than the one you posted

Gravity systems are pretty rare today as they really relied on cast iron heat exchangers with large waterways that could cope with the heat a lot longer. There are still plenty still in existence though mainly on old back boiler units and they are probably mostly working well too! Todays boilers with their low water content and aluminium heat exchangers just would not cope with a gravity system.

There are gravity systems being used in solar systems today but I don't really get involved with that side so don't know too much about it.

Jon

 

[eveares]

Gravity systems are pretty rare today

Well my Granddad used to be a plumber in the 50's & 60's and so fitted the central heating system in his house him self. I remember me helping him clean his old back boiler out; system was the back boiler what had a gas fire on the front what fed a indirect HW tank and the radiators in his house. Initially just the CH circuit was pumped IIRC, but later both the CH & HW circuit were pumped.

Later on in the early 2000's, he replaced the back boiler with a modern wall hung boiler (still gravity fed with expansion tank) along with the Honeywell Smartfit system in the Y confiquration.

In his current bungalow what my grandparents moved into back in September, the boiler is a old Ideal Logic+ IIRC and the system is all micro bore what is fed down the wall from the loft. HW is still a gravity fed indirect tank though and has been run on a really long route and is barley insulted - takes ages to draw hot water off. There also seems to be a disconnected and unused round thin expansion vessel in the loft?

Also, who else like me was taught the trick of brushing on washing up liquid mixed with water for detecting gas leaks when they were younger; do today's plumbers and gas engineers still use this technique or do they instead use high tech CO meters and other similar pieces of expensive equipment.

Picture below is me cleaning the old back boiler out:

Cleaning old back boiler as child.

• eveares
• 3 Jan 2016

Another picture of me messing around with some spare bit's my Graddad had laying around:

Messing around with old CH pump and expansion tank

• eveares
• 3 Jan 2016

 

[Aquaheat]

Us gas engineers would never use a CO meter to detect a gas leak

Nice old photos though. Wish I had some with my old man.

Jon

 

[Calmore]

You can buy "gas leak detector fluid", which I think is just an industrial detergent mixed with water!

I was told by someone that fairy liquid contains salt which can cause corrosion issues, whereas the pukka liquid doesn't, but I don't know how much truth there is in that.

 

[eveares]

You can buy "gas leak detector fluid", which I think is just an industrial detergent mixed with water!

So expensive gas leak detection equipment has not replaced detergents/liquid based detection methods.

Also, my Spirotech MB3 came today; I have a mini pipe cutter, but I only have a fingers width between the return pipe and the wall. Don't really want to use a hacksaw as pictured by the MB3's instructions, but o-well I guess I will just have to see how I get on with the pipe cutter first.

 

[Scarum]

If there's not much space between wall and pipe check the filter will actually fit before you cut.

 

[eveares]

Just an update, I have now installed the SpiroTech MB3 Filter. Not bad for some one who is not a plumber by profession, although one of the more simpler jobs I guess.

Also flushed the system out with the Fernox F5 express cleaner before and then of course put in the Fernox F1 express inhibitor in afterwards.

Spirotech MB3

• eveares
• 11 Jan 2016

Spirotech MB3 Close Up

• eveares
• 11 Jan 2016

Oh, and for those who are wondering what my boiler is, it is a Vaillant ecoTEC Plus 937.

Also, should I put another bottle of the F1 inhibitor in the system or is the 1 enough? While I only have 10 radiators, it's a 4 bedroom house and a lot of the radiators are double or large-ish ones.

Regards: Elliott.