pumped or not pumped cylinder

[baggielad]

This may be a stupid question, but I'm replacing an indirect hot water cylinder and I'm not sure whether it's gravity fed or a pumped system. There is a pump in the boiler but could this just be for the central heating and not the hot water coil in the cylinder, or the fact that there is a pump means that both circuits are pumped?

The boiler is an Ideal Mexico RS3/80.

Thanks for any replies and apologies if it is a stupid question!

 

[stem]

If the pump is for the radiators and the hot water, there will usually be a motorised valve like this to control its flow.

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• stem
• 1 Apr 2010
• 8

Is there?

With the radiators switched off, switch on the hot water only. Does the pump come on? If so, the hot water is pumped, if only the boiler fires up, it's gravity.

If the hot water is gravity fed there will be two large diameter pipes probably 28mm that connect the hot water cylinder coil directly to the boiler flow and return.

 

[baggielad]

Thanks for the reply

If the pump is for the radiators and the hot water, there will usually be a motorised valve like this to control its flow.

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• stem
• 1 Apr 2010
• 8

Is there?

I am not currently living there so I'll check next time I'm there.

With the radiators switched off, switch on the hot water only. Does the pump come on? If so, the hot water is pumped, if only the boiler fires up, it's gravity.

All the rads have been removed so I cant run the system.

If the hot water is gravity fed there will be two large diameter pipes probably 28mm that connect the hot water cylinder coil directly to the boiler flow and return.

There are two 28mm pipes feeding the cylinder coil so is it safe to assume that it is gravity fed?

The reason I asked the original question is that I ordered a cylinder from screwfix but when it arrived it said on the packaging that it could only be used for pumped systems (no mention of this on Screwfixes' website). So I rang the manufacturer and was informed that if there was a pump then it probably is a pumped system. He also said that it's hard to source a gravity fed indirect cylinder However, they will make one but it has to be a special order. I have since found some on the internet, so if it's a gravity system I'll just have to send the Screwfix one back and order a new one.

 

[JohnD]

would be better to convert it to fully pumped. It will heat up faster, and, with the aid of a cyl stat and motorised valve, will be much more economical especially in summer, especially if you lag the pipes well between boiler and cylinder.

post some pics of the pipe layouts round the boiler, cylinder and pump.

 

[baggielad]

would be better to convert it to fully pumped. It will heat up faster, and, with the aid of a cyl stat and motorised valve, will be much more economical especially in summer, especially if you lag the pipes well between boiler and cylinder.

post some pics of the pipe layouts round the boiler, cylinder and pump.

Thanks for the reply. I would be interested in doing this and I'll take some pictures when I'm next at the house.

However, I have already taken a picture of the cylinder for an earlier thread //www.diynot.com/forums/viewtopic.php?p=1565058#1565058 and as the system is currently a primatic one I am therefore adding a second f&e tank and replacing the cylinder.

Here is the picture of the cylinder

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• baggielad
• 2 Apr 2010
• 3

I'll post some more pictures when I have them.

[/img]

 

[JohnD]

as the pump does not appear to be close to the cylinder, I expect it will be easiest to locate the valve near to the boiler.

See what the make and model of your programmer are, and take a pic. Often you can reconfigure an old programmer to work with Gravity or Pumped HW, if not, this is a time to be thinking about buying a new one.

You will be fitting a thermostat to the cylinder to turn off the supply once the cylinder is hot. You will need to run a cable from the cylinder stat to the boiler electrics. The wiring is not very complicated. You can get a "wiring centre" which is a fancy junction box for all the wires to go into without cramming. It is an advantage to buy a programmer and valve of the same brand as they will have a wiring diagram you can follow, but you can get diagrams even if brand is different.

 

[robbie77]

Baggie, I don't know if you have seen my thread but I had to get my head around a pumped system so it may help a little...


//www.diynot.com/forums/viewtopic.php?t=222206&highlight=[/list]

 

[Nige F]

would be better to convert it to fully pumped. It will heat up faster, and, with the aid of a cyl stat and motorised valve, will be much more economical especially in summer, especially if you lag the pipes well between boiler and cylinder.

post some pics of the pipe layouts round the boiler, cylinder and pump.

Thanks for the reply. I would be interested in doing this and I'll take some pictures when I'm next at the house.

However, I have already taken a picture of the cylinder for an earlier thread //www.diynot.com/forums/viewtopic.php?p=1565058#1565058 and as the system is currently a primatic one I am therefore adding a second f&e tank and replacing the cylinder.

Here is the picture of the cylinder

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• baggielad
• 2 Apr 2010
• 3

I'll post some more pictures when I have them.

[/img]

That is not a primatic It`s an incorrectly piped cylinder with an annulus heat exchanger . the pipe from the flow @ the top( vent) should be 22 mm and a cold feed should go to the bottom return , in 15 mm. That annulus type will work well on gravity - better than a coil. Change the pipes and insulate it well - save money and keep it simple . Just read your other thread . God knows why they didn`t fit a F+E tank in the first place . that has been bodged into your 1 cold storage tank by the sound of it . You just need a proper F+E with cold feed and vent as I`ve described - IF you really want to pump it - and keep that annulus tank - then pump it from the bottom up otherwise you can get air trapped in the top of the annulus ( i like that word ) and it`ll make trickling noises . Been, Done , got the T shirt

 

[baggielad]

God knows why they didn`t fit a F+E tank in the first place . that has been bodged into your 1 cold storage tank by the sound of it . You just need a proper F+E with cold feed and vent as I`ve described - IF you really want to pump it - and keep that annulus tank - then pump it from the bottom up otherwise you can get air trapped in the top of the annulus ( i like that word ) and it`ll make trickling noises . Been, Done , got the T shirt

Thanks for the replies. As to why there is only one f&e tank there was a label stuck on the cylinder which although I attached photo of it to the other thread, it was in bits and therefore hard to read, but it did state on it that only one f&e tank was required.

I've taken some more pictures and here they are.

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• baggielad
• 27 Apr 2010
• 1

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• baggielad
• 27 Apr 2010
• 1

The boiler is next to a cupboard and all the pipes are in there. The pipes are, going left to right, two 28mm flow and return for the heating coil in the cylinder, two 15mm main cold water pipes and then two 22mm pipes for the heating (which is a single pipe system).

The main reason for changing the cylinder is that I'm not keen on the air bubble principle of keeping the water separate. Does that apply to an annulus cylinder?

As to JohnD's suggestion I wouldn't mind changing to a pumped system if it's not too complicated . I've looked at Screwfix's selection and I can see they sell packs such as this.

http://www.screwfix.com/prods/94777...ls/Hortsmann-312B-Heating-Control-Master-Pack

Sorry, but I forgot to take a picture of the timer.

However, how do you connect up the pipes feeding the coil in the cylinder to the pumped circuit on the boiler?

 

[Agile]

It would be very unusual for anyone to want to fit a gravity cylinder rather than converting to a pumped system.

Nor would it meet the building regulations either!

If you cannot do it yourself then you need professional help.

Tony

 

[baggielad]

It would be very unusual for anyone to want to a gravity cylinder rather than converting to a pumped system.

Nor would it meet the building regulations either!

Thanks for the reply, so under building regs if you want to replace a gravity fed cylinder you also have to change the system to fully pumped?

If you cannot do it yourself then you need professional help.

This might well be the route I'll have to take , but I'll wait to see what if any other replies I get first.

Also, thanks to Robbie77 for the link. I'll have a good read of it to see what tips I can pick up.