Can you have storage hot water system with a combi boiler in the same property?

tallac

I'm going to buy a house which has multiple bathrooms (at least 2, possibly 3). Each bathroom has a shower and I'd like it to be possible for someone to use each shower at the same time without being affected by what's going on with the water elsewhere; or at the very least 2 of the 3 showers being used at the same time. I'm thinking a mega flo type storage hot water system would work for this.

However, I like the idea of being able to have instant hot water for the kitchen or bathroom sinks. If the storage boiler isn't ready yet, then would having a smaller combi boiler just for those taps be a smart decision?

Is it a good idea to have both a storage boiler and a combi boiler for what I describe?

rob7475

I'd get someone out to measure the flow rate into the house. This will help determine what your options are. If you have good flow, you may get away with having a high output combi, maybe one of the showers could be electric etc.

Undervalued

Yes you can. A combi boiler can heat a hot water tank just like any other boiler. You can then have some things fed direct from the combi and some from the tank.

Whether that is the best answer for your situation needs looking at carefully but it is certainly a possibility.

Browntoa

I have a system boiler and a megaflo.

Instant hot water at all times , no need for a combi boiler for that . Boost button on the timer to heat water if needed. 

Our megaflo also has an Immersion heater that has come in useful if the boiler fails to work 

tallac

Following reading these posts, I did a bit more research on things and I think what would be a good solution is a system boiler with a megaflo storage tank. I've always been keen with the brand Vaillant so my preference is to get a Vaillant system boiler. Megaflo seems to be the best brand for the storage tank but does Vaillant have their own version? If yes, how does Vaillaint compare to Megaflo with regards to pressurised storage tanks?

I also like the idea of the storage tank containing an immersion heater. I assume this means you can heat the hot water via excess energy from solar PV panels too?

nofoollikeold

1. A system boiler is not a combi, so you wouldn't get instant hot water at selected taps.
2. My own preference is for heat only boilers, installed with a sealed system.  That way all the ancillaries like pumps and expansion vessels are your own choice, and you are not tied to boiler manufacturer's prices for replacements.
3. Vaillant do make their own unvented hot water cylinders, called uniStor.  They are well made but expensive.  If you use Vaillant controls, the unvented hot water system integrates very well.
4. Megaflo is a good make, but there are many others, some thought to be better than the HeatraeSadia product.  OSO, Vaillant and Joule spring to mind.
5. Don't even think about an unvented cylinder unless you can get 1.5 bar DYNAMIC pressure (pressure with one outlet running) and a flow rate of 20 litres per minute.