Heat line caprize 28a

[Alwaysworking]

Guys,
First posting, so be gentle.
I'm due to move in a couple of weeks and I will be adding a couple of en-suites to the house, currently a Heat Line 28a is fitted and I understand that it's fairly new. My question is whether this boiler is big enough to deal with 3 showers and the usual stuff that goes on in a house.

If this is a small unit, which unit would you advise to replace.

Thanks
AW

 

[Roger Welton]

If you're adding 2 more bathrooms you don't want a combi full stop. Heat lines aren't the best regarded, cheap cheap cheap

 

[Ray Stafford]

No, it isn't, at least, not if you want to use 3 hot water outlets at the same time.

Any 28 kw combination boiler (regardless of make) will only give you about 11 - 12 litres per minute of hot water. The only way to get more is to sacrifice temperature - so you get more litres per minute, but at a lower temperature.

To make 2 outlets run at the same time, you really need at least a 35 - 40kw combi, and even then it will be relatively poor. Combis are not designed for multiple draw offs.

You have a few options:

• Upgrade your combi to a 40kw - it won't solve the problem, but it will make it a bit more bearable when 2 outlets are used. A poor solution, and I don't recommend it.
• Leave your system as it is, and fit electric showers in the new ensuites. Probably the cheapest solution, subject to the cable runs being practical, and to the point below about cold water mains supply.
• Rip it all out, and put in a decent system designed to cope with multiple outlets. The best solution, but the most expensive.

Before choosing any of these, you would need to test both the flow-rate and the pressure of the cold supply into the building.

Good luck

 

[IDCHAPPY]

Boiler is ok, most combi boilers struggle when 2 or more outlets are opened though buddy.

 

[Alwaysworking]

I currently have a Vallant boiler with a 250ish ltr hot water tank and to be honest it's okay but I was looking to get a combi in order to not have to heat up a tank, is this the sort of set up I should be looking at?

AW

No, it isn't, at least, not if you want to use 3 hot water outlets at the same time.

Any 28 kw combination boiler (regardless of make) will only give you about 11 - 12 litres per minute of hot water. The only way to get more is to sacrifice temperature - so you get more litres per minute, but at a lower temperature.

To make 2 outlets run at the same time, you really need at least a 35 - 40kw combi, and even then it will be relatively poor. Combis are not designed for multiple draw offs.

You have a few options:

• Upgrade your combi to a 40kw - it won't solve the problem, but it will make it a bit more bearable when 2 outlets are used. A poor solution, and I don't recommend it.
• Leave your system as it is, and fit electric showers in the new ensuites. Probably the cheapest solution, subject to the cable runs being practical, and to the point below about cold water mains supply.
• Rip it all out, and put in a decent system designed to cope with multiple outlets. The best solution, but the most expensive.

Before choosing any of these, you would need to test both the flow-rate and the pressure of the cold supply into the building.

Good luck

 

[Ray Stafford]

I currently have a Vallant boiler with a 250ish ltr hot water tank and to be honest it's okay but I was looking to get a combi in order to not have to heat up a tank, is this the sort of set up I should be looking at?

AW

Yep. Its back to schoolboy physics.

The definintion of a watt is the amount of energy required to heat 1 litre of water by 1 degree C in 1 hour.

If you plan to run 3 outlets, each of which require (say) 10 litres per minute of hot water (and that is not generous), then you will need 30 litre per minute.

Say an average temperature rise of 35 degrees, and thats 30 x 35 x 60 (to convert minutes to hours) = 63,000 watts or 63 kw of power needed to do that in real time.

Thats why we store hot water when we might need lots of it - because the energy budget required to heat it in real time is so vast.

 

[Alwaysworking]

Is it possible to keep the Heat Line to heat water in an unvented tank? or is it a case of all out...

Ta
AW

 

[IDCHAPPY]

Ray is his usual eloquent self and is spot on

 

[Ray Stafford]

Is it possible to keep the Heat Line to heat water in an unvented tank? or is it a case of all out...

Ta
AW

Yes, you could re-use the boiler as a system boiler (and perhaps leave the combi hot water outlet to kitchen and utility room) and drive an indirect cylinder for the bathrooms.

But without wishing to run Heatline down, it is a budget-end appliance. You can polish a poo, but there will always be limits to how bright it shines. There is also a limit to what can be designed on an internet forum.

Can I suggest that you probably need to get a good, recommended gas engineer in now? Maybe post in the "I need a plumber" section?

 

[Alwaysworking]

Thanks Ray/Guys

AW

 

[Alwaysworking]

Thanks Ray/Guys

AW

 

[Chalked]

Yep. Its back to schoolboy physics.

The definintion of a watt is the amount of energy required to heat 1 litre of water by 1 degree C in 1 hour.

If you plan to run 3 outlets, each of which require (say) 10 litres per minute of hot water (and that is not generous), then you will need 30 litre per minute.

Say an average temperature rise of 35 degrees, and thats 30 x 35 x 60 (to convert minutes to hours) = 63,000 watts or 63 kw of power needed to do that in real time.

Thats why we store hot water when we might need lots of it - because the energy budget required to heat it in real time is so vast.

Excellent post :coolgleamA:

 

[Ermintrude]

A watt is defined as a joule per second of energy flux.

But good analysis.

 

[Mike Jackson]

I'd be looking at adding an unvented cylinder (assuming the incoming mains cold flow rate is good enough) and retaining the heatline boiler for the moment. When the heatline packs up you can then fit a decent boiler (intergas).

 

[Alwaysworking]

Okay that's where I've been going wrong, I had been told that about Intergas and for some reason Heatline got stuck in my head as the good unit and I could't understand why is was being called a budget unit!. Well that makes it a lot easier, I don't mind ditching a cheap units, would prefer to have taken out and re done.

Out of interest, roughly how much am I looking at, there's enough room for the boiler and cylinder to go side by side, where the existing boiler is currently

Thanks for all your help guys
AW

 

[Ermintrude]

I'd be looking at adding an unvented cylinder (assuming the incoming mains cold flow rate is good enough) and retaining the heatline boiler for the moment. When the heatline packs up you can then fit a decent boiler (that burns gas, Baxi or ideal).

Fixed your typo

 

[Ermintrude]

Okay that's where I've been going wrong, I had been told that about Intergas and for some reason Heatline got stuck in my head as the good unit and I could't understand why is was being called a budget unit!. Well that makes it a lot easier, I don't mind ditching a cheap units, would prefer to have taken out and re done.

Out of interest, roughly how much am I looking at, there's enough room for the boiler and cylinder to go side by side, where the existing boiler is currently

Thanks for all your help guys
AW

Fit an ACV sl nice and small for its physical size puts out 15% more hot water faster than Every other cylinder on the market.

Boiler. Ideal vogue or ideal logic system both superb and very reliable.

 

[Alwaysworking]

Guys, I was talking to a heating engineer today and he's saying that a Vaillant 937 would be a good choice, without seeing the setup, as I've not yet moved in?

Is this unit any good?

AW