Mega flo for a loft conversion. Do I really need it?

[niznet]

Hi there. I am about to undertake a loft conversion of a 3 bedroom semi-detached house. We have 1 bathroom, 1 WC at present. With the loft conversion, we are hoping to add an extra bathroom with bath shower+WC. We currently have a Vokera Combi boiler.

During the various quotes we were given, a couple of builders recommended having a mega-flo system, whilst a couple of others said the current boiler should be fine. One even suggested we could add a pump, as my main concern was about the pressure on the shower, not necessarily the hot water (as we will only have 2 bathrooms). My current shower gives a trickle of water and I don't want the loft shower to be equally weak (or worse).

Do I really need a mega flo? Can I get a pump with a combi boiler??? I thought you'd need a hot water cylinder (isn't that the same thing as a mega flo) for a pump. And aren't pumps noisy anyway?

Any advice is appreciated as if I need a mega flo, I would rather plan for a space to put it into the conversion before all the work is done...

 

[ColinJacobson]

Try one of these:
//www.diynot.com/forums/viewtopic.php?p=1774282#1774282

 

[ColinJacobson]

Would it not be cheaper to add another combi boiler and do not connect up the CH? These things are about £300 in B&Q. As it will be connected as an instant water heater and not used much it should be reliable.

 

[mickyg]

Would it not be cheaper to add another combi boiler and do not connect up the CH? These things are about £300 in B&Q. As it will be connected as an instant water heater and not used much it should be reliable.

thats a stupid idea. it will likely be very unreliable as it will probably never condense and the main hex and recuperator will get a battering. Not only that a £300 boiler will be a piece of junk regardless how much you use it.

Megaflo idea is probably the best one. You cant put a pump on a combi and even if you could it wouldnt improve its performance.
You've got 2 "sensible" choices. A bigger more powerflul combi or an unvented cylinder such as a megaflo(brand name).

 

[ColinJacobson]

Would it not be cheaper to add another combi boiler and do not connect up the CH? These things are about £300 in B&Q. As it will be connected as an instant water heater and not used much it should be reliable.

thats a stupid idea. it will likely be very unreliable as it will probably never condense and the main hex and recuperator will get a battering. Not only that a £300 boiler will be a piece of junk regardless how much you use it.

Megaflo idea is probably the best one. You cant put a pump on a combi and even if you could it wouldnt improve its performance.
You've got 2 "sensible" choices. A bigger more powerflul combi or an unvented cylinder such as a megaflo(brand name).

Megaflows take up space in loft conversion. The main reason for the conversion is to get space, so why clutter the space up?

I know someone who connected up a combi as an instant water heater and it was a great success. Why would it get a battering more than other types of running? It is no different to running a combi in summer when the CH is off.

Unreliable? The Heatline combis are supposed to be good and very cheap. Are they owned by Vailllant? He can keep the existing combi and extend its CH to the extension and have a new DHW only connected combi near the extension. He saves a ton of money, space, mess, inconvenience and gets instant DHW. I can't see anything wrong with it.

 

[mickyg]

Megaflows take up space in loft conversion. The main reason for the conversion is to get space, so why clutter the space up?

because, assuming the op has an adequate supply, it will be able to provide enough pressure to run more than one outlet at a time, comfortably, something most combis struggle to do. Adding another combi is gonna need almost as much room as a cylinder so hows that any better?? not to mention the gas supply? probably need to upgrade the supply change the meter yadayada, stupid idea.

I know someone who connected up a combi as an instant water heater and it was a great success. Why would it get a battering more than other types of running? It is no different to running a combi in summer when the CH is off.
.

because in hot water mode modern boilers dont do much condensing, the heat exchanger will be running hotter all the time, it will die earlier, ive seen it, real world experience(hint hint)

Unreliable? The Heatline combis are supposed to be good and very cheap. Are they owned by Vailllant? He can keep the existing combi and extend its CH to the extension and have a new DHW only connected combi near the extension. He saves a ton of money, space, mess, inconvenience and gets instant DHW. I can't see anything wrong with it.

yes unreliable. especially heatlines, total junk. Vaillant bought them out for their radiators and AC units, the boiler side will either be wound down or just kept knocking out rubbish tat for landlords and cheapskates.
how will it save money exactly? space? mess? wtf?
i can see many things wrong with it, ive gave you a few, but its obvious your not in the industry else you wouldnt have said it.

 

[muggles]

Would it not be cheaper to add another combi boiler and do not connect up the CH? These things are about £300 in B&Q. As it will be connected as an instant water heater and not used much it should be reliable.

If a water heater is needed, why not buy a water heater? Buying a combi and only using it as a water heater is just daft

 

[ColinJacobson]

because, assuming the op has an adequate supply, it will be able to provide enough pressure to run more than one outlet at a time, comfortably, something most combis struggle to do. Adding another combi is gonna need almost as much room as a cylinder so hows that any better??

I have seen some powerful combis that can do many taps at once. Are you serious when you say a wall mounted combi takes up the same space as a cylinder? I have seen both you know.

because in hot water mode modern boilers dont do much condensing, the heat exchanger will be running hotter all the time, it will die earlier, ive seen it, real world experience(hint hint)

That is the same with any of these combis then, especially in summer when there is no CH.

i can see many things wrong with it, ive gave you a few, but its obvious your not in the industry else you wouldnt have said it.

I don't have to be in the industry to know that a combi setup as an instant water heater is far cheaper and less hassle and mess. You are the first I have heard of that slags Heatline. I am not saying you are wrong, but most say they are well made and cheap. Set up as a water heater most of the time it is not being used, so the components must last longer. The diverter valve is not moving.

I did as search...
//www.diynot.com/forums/viewtopic.php?p=969592

This interesting thread said that a BIASI is efficient and they condense when doing DHW only.

 

[ColinJacobson]

Would it not be cheaper to add another combi boiler and do not connect up the CH? These things are about £300 in B&Q. As it will be connected as an instant water heater and not used much it should be reliable.

If a water heater is needed, why not buy a water heater? Buying a combi and only using it as a water heater is just daft

See this thread...
//www.diynot.com/forums/viewtopic.php?p=969592

Also you can use the combi for CH later if you needed to. Combis are cheap which is one of my points.

 

[niznet]

Thanks guys.. not sure if I'm more confused.

The builders for the conversions said that the boiler we have should be fine. My main concern is that the flow of water may become poorer in the loft, as it is another floor above. I am told that the combi-boiler we have should be able to deal with another bathroom (I assume when they say this, they are talking about ability to heat rather than flow).

When would something like a mega-flo be useful (in terms of number of rooms to heat/bathrooms?).

 

[DavidDaft]

Thanks guys.. not sure if I'm more confused.



When would something like a mega-flo be useful (in terms of number of rooms to heat/bathrooms?).

It all depends on usage i.e how many outlets will be used at the same time,a combi won't run a bath and a shower at the same time for instance

 

[Corgigrouch]

I don't have to be in the industry to know that a combi setup as an instant water heater is far cheaper and less hassle and mess. You are the first I have heard of that slags Heatline. I am not saying you are wrong, but most say they are well made and cheap. Set up as a water heater most of the time it is not being used, so the components must last longer. The diverter valve is not moving.

You know **** all about **** all so **** off!

OP, provided your water supply is up to the job, then an Unvented cylinder is the way to go. Doing things right is rarely cheap but the result is so much better

 

[ajstoneservices]

He must have upset your mate

 

[Kaboooom]

Mr Jacobson was on the right road. A combi can be a multi-point and gives scope to add another CH zone later. It does save space. It could do the CH & DHW of the extension, not interferring with the existing installation. If it has a shower en-suite then a 24kW Heatline would do.

Fitting in an expensive unvented cylinder that will not improve matters as corgigrouch says, is a typical plumber mentality. Big money for little result.

The existing combi will not do two bathrooms. The best way is what ColinJ said with less mess and expense. Of couse this is me not knowing the full layout. One thing is certain I would not fit an unvented cylinder in this situation. These cylinders are also expensive to repair having complex, expensive pressure controls.

 

[Kaboooom]

He must have upset your mate

Or sees expensive, needless work evaporating.