M
mysteryman
That is precisely why I have suggested that you keep it simple - one boiler, one cylinder, weather compensation, all one make. It will do the job. All you need worry about is getting a good cold water supply.
How much space required for this plant room?
- Thread starter indus
- Start date
Sponsored Links
I dont remember you calling me to help!
Better to call a boiler engineer rather than a plumber. Plumbers deal with water supplies, bathrooms, drainage etc. and they are perceived to be cheaper than someone who specialises in heating.
Dont expect to get a real expert from BG etc.. They are into a mass market of repairing common boilers.
As a matter of interest what was the fault? I doubt it was anything very complicated.
Tony
Yes retirement is great, recommend it to anyone that makes it 
The job was just one cylinder, I'll fire up the other computer and see what else I still have.
Expansion vessel in the corner is for the domestic cold water, next is the pump set, twin pumps that change over, then the sectional fibreglass tank on the right.
Most of our clients would opt for a yearly maintenance contract, which gave them access to a 24/7 emergency number, with a 2hr response time, even Christmas day.
The other important requirement from the client is an as fitted drawing and all the system details in a nice folder.
Ok all this costs, and is why they quite often settle for a system that is disappointing at best.
The job was just one cylinder, I'll fire up the other computer and see what else I still have.
Expansion vessel in the corner is for the domestic cold water, next is the pump set, twin pumps that change over, then the sectional fibreglass tank on the right.
Most of our clients would opt for a yearly maintenance contract, which gave them access to a 24/7 emergency number, with a 2hr response time, even Christmas day.
The other important requirement from the client is an as fitted drawing and all the system details in a nice folder.
Ok all this costs, and is why they quite often settle for a system that is disappointing at best.
Mysteryman, sorry if my earlier comment seemed rude Could you please tell me how your suggested system would provide the required pressure, flow and hot water during my peak demands?
Tony, I wasn't on this site when I had the problem, otherwise I would have taken any help offered! You are right the problem wasn't complicated, the boiler was knackered. But nobody (except the last one!) could tell me that with any confidence. I heard this line many times back then....
'someone has put your system together all wrong mate. Maybe that's how they did it in the old days. I'd rip it all out and stick a Mega Flo in if I were you'
Thanks doitall. Out of interest (as a very ballpark figure) what did the set up in the pic cost the client?
Could you please tell me how your suggested system would provide the required pressure, flow and hot water during my peak demands?Tony, I wasn't on this site when I had the problem, otherwise I would have taken any help offered! You are right the problem wasn't complicated, the boiler was knackered. But nobody (except the last one!) could tell me that with any confidence. I heard this line many times back then....
'someone has put your system together all wrong mate. Maybe that's how they did it in the old days. I'd rip it all out and stick a Mega Flo in if I were you'
Thanks doitall. Out of interest (as a very ballpark figure) what did the set up in the pic cost the client?
Sponsored Links
M
mysteryman
That's OK. From the information given, I think you will need a seriously large break tank fed from the cold main, and a boost pump set. This is how it would be done in a hotel, for example. There are other devices called accumulators to do the job, but I do not believe they will give the flowrate you are looking for from your cold main. These items will be from another manufacturer. My proposals for the heating equipment represent excellent advice.
I would budget around £10k for materials and a total budget up to £20k to include labour and materials.
There really is so many variables it's not practical to just guess.
You need someone to survey the project and discuss the ins and outs with you on site and then come up with scheme to suit your budget.
There really is so many variables it's not practical to just guess.
You need someone to survey the project and discuss the ins and outs with you on site and then come up with scheme to suit your budget.
Who me ?.
Looks like a domestic Company into solar and fancy controls.
I don't think you realise just what is involved in getting a system this size to function to a high spec.
John Brookes of CC is about the only one I would recommend to be honest, there's a couple more but they are up country.
M
mysteryman
Of course I realise. Don't be so patronising.
Sorry didn't mean it to sound that way if it does.
Mysteryman, thanks for the recommendation. Could you kindly give me a little more information as to how this 'twin coil cylinder' works? Is it a Thermal Store type set up or an unvented cylinder?
How exactly is the water heated?
Doitall, thanks. Out of interest, when you have a two cylinder/two boiler/booster/break tank set up how exactly does it work in practice?
For example lets say there are two 300l cylinders. Two showers are running in the morning at 10l/min, that gives 300/10/2 = two 15 minute showers. During this time I take it the booster is providing adequate flow rate to keep both showers running optimally.
When the hot water in these two cylinders is depleted what happens then? The boilers kick in and heat extra water (from the ?break tank) to replete the cylinders?
I really would appreciate an answer to this if you have time.
Many thanks for your kind help
How exactly is the water heated?
Doitall, thanks. Out of interest, when you have a two cylinder/two boiler/booster/break tank set up how exactly does it work in practice?
For example lets say there are two 300l cylinders. Two showers are running in the morning at 10l/min, that gives 300/10/2 = two 15 minute showers. During this time I take it the booster is providing adequate flow rate to keep both showers running optimally.
When the hot water in these two cylinders is depleted what happens then? The boilers kick in and heat extra water (from the ?break tank) to replete the cylinders?
I really would appreciate an answer to this if you have time.
Many thanks for your kind help
G
gaswizzard
Booster pumps draw water from the break tank to feed water into unvented cylinder/s.(safety issues aside)
Two 300 litre hot water tanks will supply two 10 litre shower heads for aprox 40 minutes (65c hot/15c cold).
Hot water tanks are heated via the boiler , booster pumps/break tanks have no bearing on this , cylinder will start to reheat before all hot water is depleted , if each coil is rated at 25kw then simple maths will tell you the reheat times from cold.
The water in the cylinders is never 'depleted', in that the cylinders are always full of water, but the water simply gets colder as hot water is drawn off and replaced with cold water from the storage tank or mains.
The hot water is stored at a nominal 60 degC usually. The cylinder temperature will usually be controlled by a thermostat which will turn off at 62 degC and turn on at 58 degC roughly. When the water cools to 58 degC, the thermostat turns on the boiler and pump, circulating hot water from the boiler through the coil in the cylinders until the stored hot water reaches 62degC again. Precise control of the temperature is not critical, most outlets will mix the water to the required temperature; 40 degC is hot enough for most people. The 60 degC storage is to prevent the proliferation of legionella.
The hot water in the boilers does not mix with the stored hot water in the cylinders.
It works exactly the same as a single boiler and cylinder.
The only difference is the cold supply will be from the break tank and booster set, that operates on a pressure switch.
You don't need massive quantities of stored water, 2 x 210Ltrs should be more than enough with some diversity, what you do need is a large delivery, maybe 50ltrs/min hot and 15ltrs/min if all 5 showers are running at the same time.
The boilers can be programmed to reheat the cylinders the same as with one.
The secondary circuit pump can be on a timer or pipe stats, depending how the building is used. for example if you use hot water all day and night a pipe stat is better. Whereas if you just use it mornings and evenings a timer is best.
All points that need discussing with the installer.
The only difference is the cold supply will be from the break tank and booster set, that operates on a pressure switch.
You don't need massive quantities of stored water, 2 x 210Ltrs should be more than enough with some diversity, what you do need is a large delivery, maybe 50ltrs/min hot and 15ltrs/min if all 5 showers are running at the same time.
The boilers can be programmed to reheat the cylinders the same as with one.
The secondary circuit pump can be on a timer or pipe stats, depending how the building is used. for example if you use hot water all day and night a pipe stat is better. Whereas if you just use it mornings and evenings a timer is best.
All points that need discussing with the installer.
As I keep saying it needs an onsite survey and the best solution put on paper.
What the Op wouldn't want, is to chuck £10k at a system that is disappointing to say the least, then have to chuck another £10k at it to put it right, and yes I've seen plenty.
Anyway Alec, nothing in the CC to say you do large domestic, other than controls, so if you want to convince me otherwise in another thread I'll listen as always. In fact I always thought you were an electrician with opentherm on the brain.
What the Op wouldn't want, is to chuck £10k at a system that is disappointing to say the least, then have to chuck another £10k at it to put it right, and yes I've seen plenty.
Anyway Alec, nothing in the CC to say you do large domestic, other than controls, so if you want to convince me otherwise in another thread I'll listen as always. In fact I always thought you were an electrician with opentherm on the brain.
A
ALEC1
thats ok DOA..
On a refurb once, I installed a 38kw ATAG boiler with a twin coil 210 litre (plumbed in seriesl)cylinder supplied by a grunfoss home booster set, with hot water priority, in a house. With two bathrooms, one with a shower with body jets, one with shower over the bath, and another shower room.
After about six months a discussion was started about why the cylinder was not bigger, naturally I was a bit concerned, but one thing lead to another, and another plumber installed a second cylinder in parallel was installed..In the process he dowsed the ATAG PCB with water, and caused no end of grief...
As I dont fall out with people in general, and clients in particular, when I was servicing the boiler I asked the client if anything had changed with the additional cylinder... no, it was fine with one cylinder, he said, so I asked why install a second one...
well the builder specified it..
well that taught me lots about hot water cylinder sizing in particular, and builders in general..
On a refurb once, I installed a 38kw ATAG boiler with a twin coil 210 litre (plumbed in seriesl)cylinder supplied by a grunfoss home booster set, with hot water priority, in a house. With two bathrooms, one with a shower with body jets, one with shower over the bath, and another shower room.
After about six months a discussion was started about why the cylinder was not bigger, naturally I was a bit concerned, but one thing lead to another, and another plumber installed a second cylinder in parallel was installed..In the process he dowsed the ATAG PCB with water, and caused no end of grief...
As I dont fall out with people in general, and clients in particular, when I was servicing the boiler I asked the client if anything had changed with the additional cylinder... no, it was fine with one cylinder, he said, so I asked why install a second one...
well the builder specified it..
well that taught me lots about hot water cylinder sizing in particular, and builders in general..
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
