Main Pressure hot water systems. Any experience?

TTony

Possibly a question more appropriate for thePlumbBoard or HeatingEngineersNet, but here goes ...

It has rapidly become very apparent that the Rayburn (aka Cheap Aga) is not up to the job of (a) cooking, (b) providing adequate hot water when required and (c) providing heat, other than within a 6ft radius of itself.  It does try to do these things, but has asked us to ensure that an oil tanker arrives weekly to feed it to enable it to continue trying.

Not entirely surprised, and a replacement system was high on our list of probable projects.

There appear to be a number of advantages to a main pressure hot water system (lose the water tank in the loft, lose the 2x hot water cylinders in the airing cupboard, provide power-shower-type water flow in the currently inadequate showers).  Some systems will allow a number of different heat sources, which'll be handy because we'll probably be installing a solar panel array sometime.

Anyone got any experiences - good or bad - of these systems??  We have good mains pressure, which seems to be the normal caveat for such systems.

frictionfraction

Been building houses for 35 years.  Go for a sealed system. All the benefits you describe plus you can drink the water from any cold tap.  Only thing to consider is that if you have over a two bed house with more then one bathroom you need a pressurised hot water cylinder not just a combi boiler,  if not you could find yourself standing under  a dribbling shower if someone turns a hot tap on elsewhere. 

spark240

Agree with above, although we have a straight Combi and whist it suffers a little when taps etc are used, its not bad and only for a few seconds....But...if you have an ensuite or 2nd shower, have an electric shower as a back uo in case boiler packs up.

TTony

frictionfraction said:

 if you have over a two bed house with more then one bathroom 

We do.

I've been reading a little on vented vs unvented systems, although it appears difficult to get unbiased comment.

What sort of building work do you do @frictionfraction ?

spark240 said:

But...if you have an ensuite or 2nd shower, have an electric shower as a back uo in case boiler packs up.

Good point.  There's already a backup system in place which would be unaffected by replacing the main system.

frictionfraction

spent most of my life running a house building company but now working part time as a consultant to developers, housing associations and councils.... don't get my hands dirty! 

LordOxygen

Defo fit an electric shower in a 2nd bathroom (if you have one) it's a lifesaver when the boiler packs up. Which ours did last month. 

boogieman

I don't know anything about the actual tech, but when some friends of ours bought a pretty big house they had a Megaflow system put in on the recommendation of the heating engineer. Worked very well by all accounts. 

FX_Munkee

I put in a boiler which contains an unvented hot water cylinder when I did the extensions ten years ago (Alpha CD50).
Honestly it's a god send, all the annoyances of combi boilers dissapear. Ours is a relatively modest 4 beds, 2 bathrooms, both showers are standard thrmostatic and work really well (probably the main reason for prerssurised hot water). Basically you can have full pressure hot and full pressure cold at the same time. If we move somewhere larger I will almost certainly be looking at a megaflow.

DarnWeight

Biggest problem we had when switching to a pressurized system (with a cylinder) was with the pipework to existing rads.  We had leaks in some pipe stretches under the concrete floor, which only became a problem at mains pressure.  Couldn't isolate exactly where it was, so had to spend a good chunk having all our downstairs rads feeders replaced by above ground pipework.  Once that was sorted, the only probs we've had are a faulty expansion vessel failing (cheap part, and a relatively quick fix).