New boiler advice, standard or combi

N

neza

Joined
29 Sep 2010
Messages
17
Reaction score
3
Location
Merseyside
Country
United Kingdom
After some advice really, I live in a small 3 bed detached built in 90,s. One main bathroom, one onsuite, 3 people.

Currently have a standard system with cylinder on landing and water tank in loft, so gravity fed, the boiler is potterton f50, never missed a beat and serviced regularly. All this is 30 years old, also have a salamander pump for hot water taps and thermostatic shower, this is 10 years old, we have 11 rads also.

So looking to update do I replace heat only boiler, copper cylinder and salamander pump ( dont know how long header tank in loft is suppose to last)or remove everything and go for a 30kw combi, will this be adequate, there's never a massive hot water demand really.
Just after some advice for right system before I get quotes.
Cheers
 
Last edited:
Sponsored Links
Get a separate electric shower on top of the gas heated hot water. A powerful combi should then be ok
 
A combi will only supply one hot water outlet properly at a time (HW tap/shower etc), the minute another HW tap is opened the flow will drop significantly. That's all reliant on how well the cold mains flow and pressure is being delivered. If you have lower pressure mains cold then the HW flow will drop significantly if either a hot or cold tap is opened ( toilet/WM etc)
 
Get your mains water pressure and flow rate checked and if its sufficient, I would convert to a combi. There are pros and cons but for the hot water usage you suggest, the benefits of a combi probably outweigh the drawbacks. 30kw will be powerful enough.
 
Sponsored Links
Need to know your incoming mains flow rate & dynamic pressure as that will determine how powerful your new combi needs to be in order to take advantage of it. The Navien NCB700 is worth a look if your mains can keep up with it
 
Keep the hot water cylinder.....You'll only have to reinstate it if we're all forced down the heat pump route in the future. :cautious:
 
I'm not a plumber.

From experience I wouldn't have another combi. Everything water wise interferes with pressure and supply of hot water.

Toilet, wash machine, dish washer, kitchen sink.
 
neza said:
After some advice really, I live in a small 3 bed detached built in 90,s. One main bathroom, one onsuite, 3 people.
Click to expand...
If you think the boiler needs replacing, just get another heat-only. You can then replace other items - cylinder, pump etc as it becomes necessary.

I wouldn't go for a combi, a friend of mine runs a gas company, and gets most of his work from combi repairs. He'd never have one in his own place. That's apart from the disadvantages others have mentioned, and the possible need to upsize the gas pipe.
 
A combi is a good choice for a small family house with predictable hot water usage.
fixitflav said:
I wouldn't go for a combi, a friend of mine runs a gas company, and gets most of his work from combi repairs.
Click to expand...
Modern combi boilers are generally very reliable. I get more call outs to motorised valves, CH pumps, external controls, leaking hot water cylinders and other bits of conventional systems than I do to well maintained and regularly serviced combis. Once you put noisy crappy shower pumps into the mix (even the ones costing a few hundred quid), a combi becomes the best choice for many people.
 
stem said:
That's an advantage for DIYers, because they can replace or fix those parts themselves. Unlike combi's which require the attendance of an RGI.
Click to expand...

That is exactly right! Once your cylinder, tank and pipework have been removed and replaced by a combi, it will cost a considerable amount to replace them, should you change your mind. Many people do change their minds after, once they realise how different a combi is. In addition - if your present gas supply pipe is concealed, the installation of a combi may well mean a new, larger capacity supply pipe, often on the surface.
 
Our rule of thumb is - where there is more than one shower/bath/basin and if the system is already stored hot water, then it would be unwise to change it. Habits change all the time and if there is the potential, at any time, for 2 showers to be running at once, or a shower and then someone opens another hot tap whilst in the shower, most combi's will never quite keep up with that demand and someone's getting a cold shower.

Keeping as it is allow the water flexibility to be retained, if it goes to a combi, you can lose that.

Of course a combi does allow some in house space recovery if that's an essential requirement. Repairs, as suggested, tend to me more complicated and therefore more expensive as most combi's are complicated beasts compared to what you have and most of the components that fail are internal, invariably needing a GSR engineer to fix it. That and again as suggested, the gas supply will undoubtedly need to be upgraded too as the F50 (18Kw) will more than likely be on a 15mm supply.
 
D

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

 
You must log in or register to reply here.
Sponsored Links

Similar threads

T
Boiler relocation to loft?
2
Replies
18
Views
4K
fixitflav
F
R
Combi VS Standard Boiler
Replies
10
Views
2K
gas4you
G
C
New Boiler recommendations, please...
Replies
8
Views
609
dcawkwell
D
M
Shower pump hot Connection
Replies
4
Views
5K
MRTR10
M
takacs
Combi boiler with cylinder
Replies
14
Views
1K
gas112
G
Back
Top