New Boiler . .fair quote?

George_Bray

EliteHeat wrote: »

The header tank performs two functions; it keeps the system topped up with water and provides an open vent to the system;
The cold feed should be teed into the return primary pipework, as should the open vent....You can combine the the cold feed and open vent but this will make the system slower to fill up and on a gravity circuit, prone to air locks.

EliteHeat

Thanks for this. Yes, it's a J25 which I want to change from indirect single feed to indirect 'standard' by adding a new header tank in the loft.

To clarify, do you suggest I take two pipes up to the loft? i.e. one for water and one as a vent (up to roof height?) But won't both pipes fill with water up to the height of the header tank?

Also, as long as these one or two pipes are connected to the return section of the indirect loop, how important is it that the connection is made at ground floor (heater) level. Or can I make them at upstairs, water cylinder level and thereby use less piping?

Regards
George

EliteHeat

I don't actually understand from your description what your current configuration is. Are you saying that you have a direct HWC heated from the J25? i.e. no internal coil?

George_Bray

EliteHeat wrote: »

I don't actually understand from your description what your current configuration is. Are you saying that you have a direct HWC heated from the J25? i.e. no internal coil?

Sorry, I used the term 'indirect' throughout but nothing is ever as simple as one hopes! My current configuration is of little interest! Let's almost ignore it and pretend I have a new house with no plumbing at all. I don't need heating - just a simple hot water system. I buy the following main components for the indirect part of the system. I'm ignoring the main water storage aspects:

(a) a small heater/boiler downstairs, designed for an indirect, gravity fed system (no circulating motor).

(b) a standard indirect water cyclinder (110 litres) for the airing cupboard upstairs, and

(c) a small header tank for the loft, with a vent pipe hovering over the top.

I understand the purpose of the header tank is to (i) top up the indirect loop and (ii) allow for expansion to prevent an explosion.

QUESTION please: regarding the connections between the header tank and the indirect heating loop. Is it essential to connect the pipes (water in, and air vent "out") to the loop at ground floor, boiler level? Or is it OK to make the connections at upstairs, water cylinder level?

Many thanks
Regards
George

EliteHeat

Aha, I see. Make the connections at the top. If you really wanted to, you could also combine the cold feed and open vent which would minimise the amount of pipe work at the cost of slower filling and the system being more prone to airlocks.

plumb1_2

George_Bray wrote: »

Sorry, I used the term 'indirect' throughout but nothing is ever as simple as one hopes! My current configuration is of little interest! Let's almost ignore it and pretend I have a new house with no plumbing at all. I don't need heating - just a simple hot water system. I buy the following main components for the indirect part of the system. I'm ignoring the main water storage aspects:

(a) a small heater/boiler downstairs, designed for an indirect, gravity fed system (no circulating motor).

(b) a standard indirect water cyclinder (110 litres) for the airing cupboard upstairs, and

(c) a small header tank for the loft, with a vent pipe hovering over the top.

I understand the purpose of the header tank is to (i) top up the indirect loop and (ii) allow for expansion to prevent an explosion.

QUESTION please: regarding the connections between the header tank and the indirect heating loop. Is it essential to connect the pipes (water in, and air vent "out") to the loop at ground floor, boiler level? Or is it OK to make the connections at upstairs, water cylinder level?

Many thanks
Regards
George

If you want to change the HWC you already have, why not just swop it like for like.

ie, PRI-MATIC cylinder, no need to install a header tank.

And my 2 penny worth, missleading info regarding the 2hrs for swop a indiret cylinder Elite is correct in his posts.

ormus

2 hrs or 4 hrs, or even 8 hrs is no matter. the 1500 quid quote, shows you why some teachers are leaving the job and training to become plumbers.

as a competant diyer, i know i can change a HW cylinder within a day.

George_Bray

EliteHeat wrote: »

Aha, I see. Make the connections at the top. If you really wanted to, you could also combine the cold feed and open vent which would minimise the amount of pipe work at the cost of slower filling and the system being more prone to airlocks.

EliteHeat

Many thanks. I'll make the pipe connection(s) to the indirect loop at the foot of the water cylinder (upstairs level), rather than take that pipe down to the boiler at ground floor level. I may try just one pipe from the new header tank to the indirect loop and see if I get any problems with air locks or anything. The speed of fill-up doesn't bother me because it's almost a one-off event isn't it? I can add a bleed valve. Over the coming years, the amount of loss through evaporation from the indirect loop will be negligible, I hope.

Plumb 1

The reason I want to avoid a pri-matic cylinder is that they strike me as bad value.

Regards
George

plumb1_2

George_Bray wrote: »

EliteHeat



Plumb 1

The reason I want to avoid a pri-matic cylinder is that they strike me as bad value.

Regards
George

Hi George, can you explain why it is bad value?

You are taking out a Primatic cylinder and replacing it with a indirect.
As you say you are going to have to install a header tank with byelaw30kit, seperate overflow, water connection, tank connection.
Run 2 pipes(good pratice)( 3 Tee system= golden rule) feed and vent fom the loft to the cylinder below, pipe,fitting, gate valves, insulation.

Trade off the cost and time to do the above, and you will have a no better system.

If you can explain the added value/advantage to changing this, please let me know.


What is the 3 Tee Rule, 1st tee vent, 2nd tee feed, 3rd tee flow.
Why is it important to fit a seperate vent &feed? if these are combined and if you get debris in the tank it could go down the combined F&E blocking the VENT, risk of explosion.

If you have 2 seperate pipes (F&E) and the feed gets blocked, then your systemwill run dry, but you will still have the safety of the Vent.

George_Bray

Plumb1

>Hi George, can you explain why it is bad value?
I understand a simple indirect cylinder is about £179 whilst a Primatic version is at least twice the price.

>You are taking out a Primatic cylinder and
>replacing it with a indirect
Yes, but to be honest there's a bit more involved which I left out to keep things simple!

>you are going to have to install a
>header tank with byelaw30kit

What's that?! Yes, it will involve a bit of work but as it's DIY I won't have to pay out any cash for labour and I already have a secondhand indirect cylinder.

>Run 2 pipes(good practice)
Won't any second pipe fill with water up to the height of the header tank? So any air which needs to escape still has to bubble up through a pipe full of water? Why are two pipes better than one, please?

>Trade off the cost and time to do the above,
>and you will have a no better system.

I understand that Primatic systems have gone out of fashion. Aren't simple indirect systems better because they are simpler with less to go wrong?

>Why is it important to fit a seperate vent &feed?
>if these are combined and if you get debris in the
>tank it could go down the combined F&E blocking
>the VENT, risk of explosion.

OK, this answers the question above. Many thanks. It makes sense. I will fit two pipes.

Regards
George

Canucklehead

Hi


I think you are trying to achieve this....http://albionwaterheaters.com/Superduty.html

I doubt this (or your own fabricated one ) will work on gravity. The only way to improve heat up time will be to add a pump.

I find it interesting that you denigrate the professional yet have no knowledge of the bye law 30 kit.(or were you just joking?) See post 13!!!

I suppose (by the tone of post 13) that you will feel I am trying to out gun you by saying that I hope none of your family suffer any ill health from contamination of your new second hand and altered cylinder. You will know exactly how to disinfect you new system as per bye laws for new installations.

Good luck

Corgi Guy.