Gravity hot water system - replace or improvement ideas please advise

[Pro heat]

I agree with all, go for unvented system But can be dangerous if installed by unprofessional person,

 

[Chuck]

I've just had a gravity circulation HW system replaced with an unvented indirect cylinder (Megaflo) getting rid of both CW store and CH header tank in the roof in the process. It was not cheap but I am really pleased with the new system. (I don't have a shower in the bathroom at the moment but it would make installing one very easy.).

The only 'gotcha' was the airing cupboard went from toasty with the old cylinder to barely warm with the Megaflo. Fortunately, space and wiring made installing a couple of low surface temp heaters and a 1-4 hour timer easy, but you may want to plan for this as part of the installation.

Make sure you use an installer with a G3 ticket (you can check them on the gassafe website) and make sure they issue a building regs compliance certificate.

C.

 

[doitmyself]

I currently have a gravity hot water system

Does the timer allow you to have central heating on by itself, or do you have to have the hot water on at the same time?

 

[Last Plumber]

Does the timer allow you to have central heating on by itself, or do you have to have the hot water on at the same time?

Hello doitmyself,
You shouldn't be able to put Heating only on with gravity hot water !

 

[Welder]

Couple of additional points.
1 - G3 compliance is NOT listed on Gas Safe site. Each installer carries a card with their details - check it.
2 - Water flow rate is VITAL for an effective UV system. You must make sure the installer knows exactly what you expect from the system into the future.
3 - Make sure it is serviced EVERY year

 

[ShaunCorbs]

Couple of additional points.
1 - G3 compliance is NOT listed on Gas Safe site. Each installer carries a card with their details - check it.
2 - Water flow rate is VITAL for an effective UV system. You must make sure the installer knows exactly what you expect from the system into the future.
3 - Make sure it is serviced EVERY year

1 it is under unvented cylinders

2 agree 100% (min I would do is 2.0 bar and 25lpm)

3 agree, if it fails and you haven't had it serviced your house insurance could be invalidated

 

[Welder]

Shaun thanks
What I really meant was that the GS site is NOT the only where G3 registration is listed. For example I'm not GS but am G3. Now I look at it, I can't find a website for mine!!

 

[ShaunCorbs]

Shaun thanks
What I really meant was that the GS site is NOT the only where G3 registration is listed. For example I'm not GS but am G3. Now I look at it, I can't find a website for mine!!

Thing where gs scores is we only have to pay 2.50 to register an unvented cylinder building control want a lot more

And there isn't one for people to check, just have to show your card and advertise your G3

Also welcome to the forum

 

[cr0ft]

To allay your fears about unvented cylinders OP, I had to cut one out that was leaking and corroding badly (10 years old, never been serviced) and replace it. The drain valve had failed and I wasn't able to syphon all the water out so had to cut a hole in the top to wet vacuum the rest of the water out so I could get it downstairs on my own.

The inner skin of the cylinder is about 5mm thick stainless steel. Strong as anything and took me an age with an angle grinder to break through!

 

[doitmyself]

Hello doitmyself,
You shouldn't be able to put Heating only on with gravity hot water !

I know that! However you are assuming that the OP is talking about a pumped heating/"gravity" hot water system. We don't know that. Some people refer to a fully pumped with cold water, from a tank in the loft, feeding the HW cylinder and hence the hot taps as having a gravity HW system, presumably as compared to a direct feed from the mains, i.e unvented cylinder.

I was trying to find out what the OP meant by "gravity HW system".