Combi or Regular boiler

Hi Johnny.

Blimey, I had to look up these reviews - 2 out of 5 score?!

Reading through, it dawned on me that they applied to ALL Worcester models, and not just the 34cdi.

I don't know if that helps or not! It depends if the 34cdi is better than the others, I guess...

What does seem to be the case is that the quality of installation is important - the system must be cleaned out thoroughly, and a filter must be installed. And with your 36 year old pipework, there is bound to be a fair amount of sludge sitting in there that'll need shifting.

Ok, having said all that, my personal thoughts are that a combi will suit you perfectly. It'll be more efficient, you will lose all that nasty plumbing up in t'loft, and you will have constant gushing hot water - hopefully out of your tap .

Doesn't the Worcester have at least a 5-year warranty? So that can't be bad...

If you like your showers, I'd be very tempted to chuck the leccy one out and have a thermostatic shower running from your combi instead - a 34kw boiler will give you a cracking shower; you'll love it .

 

The shower won't make a difference as it is an a electric instantaneous one.

Did BG come and give a quote. When I had a quote from them they recommend a Worcester 30Si (the compact version). As the gas supply was long it need upping to 28mm. And that was for a 4 bedroom, 1 bathroom house with 10 rads.

In the end we went Vailant ecotec Pro 28 using a local co, they did a power flush and it was for half the price I was quoted from BG! Apparently they are a lot easier to service as there's more room, I heard with Boschs that it could mean a total strip down.

Also Vailants comes with a 7 year warranty providing it is service from them annually - there is a catch.

This is a pic of the insides:

 

My parents had the potterton flamingo 50 in their house, they have the Worcester 27CDi, quite big in size bosch have stopped making them. It was reliable but it was changed as they had a kitchen refit. I did all the alterations - so saved them a lot of money.

http://s1383.photobucket.com/user/J...n Refit 2011/Kitchen Refit Mums?sort=6&page=1

 

I think thats overkill, to be honest you would get away with the worcester greenstar junior 28I. We had this installed in a 3 bed house with 8 rads and worked perfectly. I will have a look at the specs tommorow, i mean later this evening and let you know. Dave does gas may give a reply.

 

Just to let you know we paid £1850 for the vailant fully installed with power flush. But that was for a combi replacement in same location.

 

Jit Gang - when I said my recommendation was to throw out the leccy shower and fit a thermostatic one instead, I was aware of what I was saying! I did mean to plumb in a completely new shower control fed by hot and cold to take full advantage of the combi's goodly hot water supply.

If our clearly very sprightly (I'm not being patronising) Mr Melvin and his Mrs enjoy their showers, then they will appreciate the one provided by the combi over the sprinkle given out by even the best leccy shower, especially in this cold weather.

But obviously it would cost (but I bet he can have his boiler installed and a new shower control for the same price as BG's boiler fit...!)

Johnny, all the combi boilers mentioned above will provide more than enough power to heat your home. So the main difference between, say, the Junior '28'i and the '38'CDi - and it's a big difference in these cases - is the hot water flow out of your taps. A 38kW jobbie will give a gushing tap (and shower) of around 16 litres per minute if needed, whilst the 28kW will be around 10 lpm.

It's your call as to whether this is important.

(Your plumber will need to check that your mains water supply provides the minimum for these first, of course.)

Ah, the Vaillaint. Yep, a 7-year warranty (with, of course, annual services to pay for).

Johnny - a couple of Qs, please; Where do you live, and what's a 'footprint'...

 

A 28kW combi will give an average about just under 13 litres/minute not 10. I would keep the boiler position in the loft and have a simple timeclock down in the house. Forget Vaillant and W-B, overpriced, overrated medium to low quality stuff. Go for an Intergas combi. They are bomb proof and made like tanks. The Intergas combi has only 4 moving parts and no potentially troublesome three way valve. The heat exchanger is a dual CH/DHW made from heavy copper and aluminium. The whole of the back panel is the heat exchanger using all the space wasted on other boilers. It is quite small in physical size. Brilliantly designed. The Dutch invented the condensing boiler, so know a thing or two about boilers.

Get the Intergas HRE 36/30 Compact Combi model, it delivers 15 litres/minute DHW and fills baths up easy enough for you. Older people like or needs baths. It has NO three-way diverter valve, no DHW plate heat exchange, no air pressure switch. It has little standby losses. Fit an OpenTherm thermostat, it modulates the burner directly. Worth having for better house temperature/comfort control and lower gas bills.

It can be used as a multi-point only with the CH section dry of water and visa-versa. A 10 year warranty on heat exchanger and 2 on parts. Even if the pump fails (which is a cheap standard pump available from S/Fix even on a Sunday) the DHW works. It comes with weather compensation and have the outside temperature sensor fitted (easy from the loft). They are very quiet.

The best quality boilers are Dutch. ATAG or Intergas. The ATAG is more expensive. I always look at the Intergas for first selection before choosing a boiler. They cost less than W-B and Vaillants - about £900 inc flue for the 15 litres/minutes model, and they have weather compensation incorporated, so get the outside temp' sensor - it will save gas. The Intergas has been made for 20 years and were designed for the Dutch social housing market to be ultra reliable. Not one heat exchanger has failed in 20 years and over 200,000 have been made. They are now well established in the UK with even national chain Plumb Center stocking them. The local branch had a cutaway combi on display. Once installers fit one they never go back to inferior models as they never have the dreaded callbacks. Specify an Intergas and do not take any notice of what the "plumbers" tell you. They may be on a make up from a local dealer for a W-B or whatever.

http://www.intergasheating.co.uk/specifier/product/combi-compact-hre-3630/

Now the Intergas is here, if you have good mains water pressure and flow there is no need to fit cylinders any more if you have one bathroomed house. Things have moved on.

 

Och, I'm starting to warm to you, Walt, so let's split the difference and say a 28er gives around 11.5 lpm?

Cool.

Someone else on here - TomPlum? - highly rates the Intergas too, and I have to say the lack of moving parts sounds a huge plus. No diverter valve? No PtoP exchanger? Blimey, that sounds genuinely brilliant - these are the usual bits that go wrong.

 

28kw will give between 12.5 and 13 litres/min. Cool.

The Intergas range (they do system boilers) are one of the few boilers that are really worth considering and exceptionally well priced for what they are. They were rebadged under Atmos in the UK for years. The high pressure discharge pipe can run into a HepVo trap and brass tundish and to the main stack using high temp plastic pipe, so no having an ugly pipe through the outside wall.

The only other boiler I "think "with no three way valve is the Vokera SE non-condensing boiler at 24kW and 28kW. Again a simple very reliable boiler with fewer parts. It is used in flats a lot. A pity most plumbers haven't a clue about the exception regs as I see ugly plume pipes all over blocks of flats.

The Intergas is the only combi I know that can be open vented and fed from an Feed & Expansion tank to make them even simpler. No pressure vessel to lose pressure and break down, or needing replacing, causing a big expense. In this case with the boiler being in the loft I would fit a one pipe feed and expansion 22mm pipe to an F&E tank. The open pipe F&E tank ensures little oxygenated water gets into the system. If I recall correctly it comes with a high pressure discharge valve, but this can be capped up.

I had an open vented system boiler version of the Intergas fitted heating a thermal store, that only heated the store water, not the rads. It and the store were in a basement. The ground and first floor heating was on two CH zones. The CH was by gravity from a coil in the thermal store. No pumps on the CH. The zone valves for each CH zone were mo-mo vales, so consumed no electricity when open or closed. All the rads had TRVs. The store had an internal DHW coil. The only pump was one fixed speed standard pump in the boiler. It will go for years and years, with just two cans of X-400 in both F&E tanks every 3.5 years.

 

I do like the sounds of the intergas.

 

Yep, it goes pfffffffffffttt.

(At least I do )

 

If you have a local stockist of the Intergas, John, I'm sure they'll be able to recommend installers - they are bound to have a list.

Worth getting at least a couple out to quote. Listen carefully to what they say - you'll usually pick up on the one you feel confidence in, and hopefully he will also listen to what you want.

If there is a choice, I would personally go for a fully-sealed system (Walt was saying you could use an expansion tank with their combis if you wanted?), but surely you want all these tanks and stuff completely out of your loft?

If your loft has good access, though, you might want to consider having the whole boiler up there? Would it be good to have the free space in the kitchen?

As you say, modern boilers are much better insulated so won't heat up the room they are in the same way as the old ones did. So, even if you keep the new boiler in the kitchen, you may need to fit a radiator in there too if there isn't currently one there.

And if you do like a really good shower, then no harm in asking the guys how much extra for a thermostatic shower control instead of your instant leccy one?

Good luck - please keep us posted how you get on .

 

The Intergas is the only combi that can be vented. Others can but you bypass the makers recommendations. Many open vented boilers use the same heat exchanger as sealed system boilers. But the instruction say it must be sealed because a pressure vessel comes in the case.

There are advantages to a sealed and open system. One for sealed is that space taking tanks are eliminated. But there is space in the loft for an F&E tank so that is not applicable. The only part to fail on an F&E tank is the ballcock. A sealed system has many parts that can fail, and expensive to replace as the boiler has to come off the wall if the pressure vessel needs replacing.

If the boiler is going in the loft then I would fit a 22mm combined feed and expansion pipe to an F&E tank above the boiler. Also the homeowner can top up the system every 3.5 years himself with X-100 by pouring it into the F&E tank.

A loft mounted boiler needs lighting from the hatch to boiler and in front of the boiler. It needs to be floored from hatch to boiler and a permanent ladder (shootdown).

Elson are famed for making square combined cold tank/DHW tank. They save lots of space in flats.

If the combi is fitted it is best to balance the water system. Have a dedicated 22mm pipe from the stopcock to the combi, even if the supply from the road is 15mm. After the stopcock have a tee and all cold outlets off that. Have the shower cold off the 22mm combi feed just before the combi, then if the pressure fluctuates around the combi it affects the cold and hot of the shower. Also fit flow regulators on all hot and cold outlets. BES sell them, unfortunately s/fix do not. It is a combined isolator and flow regulator by inserting a cartridge for the flow you want. 6 litre cartridge for the sink H&C. 3 to 4 litres for washing machines/d'washers/basins/toilets. These outlets do not need to be high flow rates, as they can affect the shower's flow and pressure. Have the shower on full flow (no regulators), as with the bath taps.

The shower is king in a water system. all other outlets must not affect it.

 

Have a good one, Mr Melvin .


2 bottles of Remy?!

Oh, you will...

 

Plumb Centre had one on display and the guys knew nothing about it. I told them all about it to their gratitude.

On all modern boilers there is little radiant incidental heat from the casings. Try putting a Myson Kickspace in the Kitchen. That will heat it up pronto.

No advantage as the DHW is the same as the model beneath. The smallest combi is way big enough for your house.

Happy Birthday. Keep sober.