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Discuss Do I really need a Combi-boiler to replace my existing boiler in A1 condition? in the Plumbing Jobs | The Job-board area at PlumbersForums.net

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Hi just joined the forum. Looking forward to getting some experienced opinions here. Really quite desperate to get 2nd opinions etc....

We have a house built in 1934. Our water inlet pipe was changed to the blue plastic about 2 years ago.
We had a disconnected water softer when we moved in and had it removed an the spaghetti junction of piping in the cupboard downstairs cleaned up for efficiency (all copper).

We have however experienced constant 3 way valve failure replaced by our current plumber who also pointed out our boiler was in A1 condition which he services every year (for about 8 years).

Same plumber fitted the wrong hot water pump (salamander) and the bearings went. Apparently should have been a hot AND cold version.

He did a complete inspection of our system and advised that we still have some old iron pipes in upstairs hot water tank cupboard and that these will be what is causing the low hot water pressure (we are aware of heavy hard water in area) and that it would be a massive nightmare to remove it. He has recommended replacing our boiler with a combi and removing the very old asbestos tank in the attic and fitting a coil around the inlet all for a measly 4K.

ALL the other pipes in the house are copper and small bits of st/steel. The house is a 3 bedroom with two storey extended on side to 4 bedroom with ensuite and garage and breakfast room downstairs.

My opinion is the iron could be removed and replaced with ptfe pipe to the other copper and a coil around the inlet should solve these problems to a reasonable extent. And if a higher quality 3 way was fitted this would certainly help. Furthermore, I thought combi was for smaller houses generally?

Oh, we do have a separate power shower (pump in attic) which plumber quoting me would also remove and replace with new combi compatible version.

I'm sure a combi would solve the problems of 3 way valve failing regularly? may be? but this all appears to be overkill? AND I don't have £4K!!

Any opinions would be very much appreciated. Thank you very much :¬)
 
Convert it to an s plan system easy enough to do

But need to find out why the 3 port is failing is he just replacing the heads and not the whole body eg the valve etc?
 
I would get a second opinion from a local engineer, i wouldn't recommend a combination boiler for a house that size unless your water pressure is amazing! If your boiler is in great condition and your cold mains pressure is good, consider an unvented hot water set up or a combi with stored hot water. This would boost your hot water pressure and remove the need for the shower pump, and the 3 port valve should be lasting 10 years and if not something is killing them, maybe just cheep valves been used.
 
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You really need to supply some more info.
1. Size of your dwelling. no of rads no of bathrooms
2. Building lifestlyle...r u in all day or empty house
3. What sort of boiler at present. fuel ..nat gas, lpg oil
Beware of 'plumbers' who suggest a combi they are suitable for some applications they are not a universal answer by any means.
If your present boiler works depending on what it is it might actually outlast a modern combi (some have short lives)
Then you will get all sorts of sound advice from UKPF members based on their actual experiences ....centralheatking
 
You really need to supply some more info.
1. Size of your dwelling. no of rads no of bathrooms
2. Building lifestlyle...r u in all day or empty house
3. What sort of boiler at present. fuel ..nat gas, lpg oil
Beware of 'plumbers' who suggest a combi they are suitable for some applications they are not a universal answer by any means.
If your present boiler works depending on what it is it might actually outlast a modern combi (some have short lives)
Then you will get all sorts of sound advice from UKPF members based on their actual experiences ..centralheatking
Hi and thanks.
11 rads
2 bthroom + understairs loo bt no rad there
nat gas boiler only on twice a day sometimes forced in winter as one person home.
is it really feasible that large vertical steel pipe leading from inlet to first floor hot water tank cupboard can be killing the system due to limescale filling the bore as suggested by plumber. i read about cheap 3 way valves and suspect this may b one. hw tank is not raised off floor and why would the system be designed to need a hot water pump. the supply pressure is good to the house. a few blocked off verticals in hw tank cupboard as well. what are the likely causes of 3 way failure twice in one year? limescale or just cheap? thanks
 
Hi and thanks.
11 rads
2 bthroom + understairs loo bt no rad there
nat gas boiler only on twice a day sometimes forced in winter as one person home.
is it really feasible that large vertical steel pipe leading from inlet to first floor hot water tank cupboard can be killing the system due to limescale filling the bore as suggested by plumber. i read about cheap 3 way valves and suspect this may b one. hw tank is not raised off floor and why would the system be designed to need a hot water pump. the supply pressure is good to the house. a few blocked off verticals in hw tank cupboard as well. what are the likely causes of 3 way failure twice in one year? limescale or just cheap? thanks
Was the complete valve replaced or just the head? You could have just been unlucky, the valve should have had a 12 month warranty providing its not scaled up or covered in sludge, sometimes you just get a lemon, I wouldn't read to much into the valve issue if the previous ones have lasted years you were just unlucky. If only one person lives in the property then a combi could save you money long term as no stored hot water and will also get rid of your extra valves, pumps, etc. Just to add, the pump on the hot water may just be to boost the shower.
 
There may be cheap 3 way valves but the Honeywell 3 port is probaly the best. If yours is failing regularly, as has been suggested has he changed the body or does he just keep changing the head.
 
As suggested, but not actually explained, the valve body may be sticking or partially seized. What is he actually changing on a regular basis - we are guessing the motor or the head and not he whole thing. In itself replacing the motor or head only is not wrong, but if the valve itself os forcing the motor to work too heard it will keep repeating. I have met several guys who only change the whole thong, which IMO is not normally the right thing to do. I always changed the motor, but explained that in the event of a recurrence, the whole valve may need to be changed. Whatever, a blocked pipe is not going to cause premature failing UNLESS scale deposits are getting into the valve. The chaves are that the iron pipe is a hot water pipe which has no bearing on the 3WV.

As ever, a picture is worth a thousand words!

Combis, while having a place in the market, are often wrongly recommended by house bashers, but for longevity, stored, IMO, is best.

What does he mean by a coil around the inlet - a scale reducer?
 
I used to live and operate a plumbing and heating outfit in Bath...a very hard water area. Kettles needed de scaling 3/4+ times a year, hot water cylinders would rock up at the top nut until it was impossible to even push a sewing needle thro. It sounds like your situation. An exterior coil and restricted flow point this way. We used declomat descaling pump
until we made our own. There are modern versions of this now. You might be able to hire one. Then simply turn off incoming water main hook up the unit to the cold pipes make a circuit and pump away even add hot water to the ds3 chemicals to speed things up, do same with the hot supply. The chemicals are harmless and change colour as their power is exhausted and need replenishing. The top nut in the cylinder rocks up first, easy fix, drain cold water storage tank then undo top nut lift the pipe out of the way get a masonary bit on a lecky drill and carefully drill it away. The lime scale can be shifted to the bottom of the tank by biffing it when full. Ultimately a new cylinder is best but way cheaper than an unsuitable combi installation. centralheatking
 
Thanks. Much appreciated. Yes, we live in north Hants which is near the north downs so terrible lime-scaling. I'll take a pic tonight. I believe he changed the whole valve and then when it went again (6-8months) I suggested just changing the motor but this was argued against as suggested it would just bind up again soon. BTW-because he has qtd 4K for a complete new boiler etc, he has not actually removed the knackered hot water pump so as far as I can see, HW will still have to travel around the rotor of this Salamander pump. Suspect if this was removed and the pipework adjusted this would improve the HW flow an unknown amount. I think the galvanized iron pipe is the supply pipe. It changes to largish diameter copper in the HW tank cupboard and a shut-off valve just above that and carries on straight up so likely the attic supply pipe. I'll check tonight.

Plumber has said our whole system is in a terrible state and suggested we really need a flush through and clean though this is of course nothing to do with the HW delivery system.

Furthermore, I am suggesting a coil around a supply pipe somewhere suitable - we have nothing at the moment. I thought there might be a miracle technique out there in the market?? I heard active coils can be effective (polarise the water I assume?).

But yes, the ultimate question is what is failing the 3WV so easily?? Surely completely filled pipes can't bind up a 3WV in 6months??
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I'll also check the 3WV manufacturer tonight - seem to remember noticing it was a cheap £70-£80 plumbase type unit.
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Oh, and thanks for the advice regarding cleaning the system and HW tank nut at the top.....
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last amendment - I assume he DOES mean a scale reducing coil. I suspect some are good and some are a waste of money? any advice/ experience much appreciated.
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please see first pic downstairs. rest in hw cupboard. should see galvanised pipe changing to copper. turns out hw salamander pump is isolated. suspect whole problem is one piece of galvanised that must be caked up. also have 2into1 at sink in kitchen that being told ruined bearing in pump. however ch system needs flushing as and ruined 3wv. any suggestions re water softener please?
 

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