What kind of heating set up is this?

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Just put an offer in for a 4-bed house, this is the heating set up. What can you tell me about it? is that a system boiler or a combi.
 

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Can you explain how it works? Is the following correct?
  1. Next to the boiler is a unvented cylinder.
  2. The grey box thing is a 3 port valve which either sends the heated water into the cylinder or across the heating system (depending on whether there is demand for water)
  3. The pump is outside the boiler and is used to pump the hot water around the heating or into the cylinder (don't get this, why isn't the pump in the boiler?)
  4. The hot water runs via mains pressure, so it goes through the cylinder and then into the taps
  5. So long as the cylinder is hot you don't have to wait for hot water (so 5 people can have a shower one after the other without any down time in between)
 
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1&4. I’m no expert but I’m pretty sure it’s a vented cylinder, so no mains pressure hot water - you should have a cold water tank in the loft. Number 2 is correct. 3. Only system and combi boilers have the pump inside the boiler. Outside is easier and cheaper if you need to replace. 5. 5 people probably could have a shower as long as they are quick ones - there’s only so much hot water in a tank before it needs reheating.
 
The cylinder next to the boiler is not unvented , not sure exactly what it is as I have never seen a grade 4 copper cylinder, can you post a pic of the other side as it might be a thermal store.
 
You can get vented cylinders with main pressure hot water, but the hot coils (heat exchanger) would be duplicated, bottom heat in, top heat out, it seems you have standard Y plan.

My house the upper floor cold water also comes from the storage tank in the loft, so both hot and cold are same pressure, so simple mixer taps on the bath gives a reasonable controlled heat output to the shower head, although very low pressure. Parents house had a pump to increase the pressure, this was not at boiler or tank location.

Three port valves are either Y or W Plan the latter only used when the water store is very small, so as default with Y Plan it is domestic hot water (DHW) the tank thermostat turns on the boiler and pump.

If the central heating thermostat also calls for heat, the valve moves half way, the tank thermostat is still sending supply to boiler and pump.

If the CH is called for and not DHW the DHW thermostat sends a signal to the motorised valve, and valve moves all the way.

What throws people is the tank thermostat still controls the central heating when the DHW is hot enough, so a faulty tank thermostat can stop central heating from working.

If there is a programmer again it sends a signal when DHW is off, to move valve all the way, again I have seen it where this wire is missing.
 
Won't be able to get any more pics until I visit again (which won't be any time soon).

With regards to the system, assuming everything works ok I guess there's no point converting to a combi system?

Anyone know anything about that boiler, is it solid? It looked quite new to me
 
Next to the boiler is a unvented cylinder.
No that is a vented cylinder


don't get this, why isn't the pump in the boiler?
Because it is a heat only boiler , not a system boiler

The hot water runs via mains pressure, so it goes through the cylinder and then into the taps
Nope it is open vented HW so not mains HW, but as @picasso says as it is an Albion it might be a thermal store so post pics of the other side of the cylinder.

So long as the cylinder is hot you don't have to wait for hot water (so 5 people can have a shower one after the other without any down time in between
No chance
 
So do you think I should replace it with a combi or not?

Not sure I like the idea of having an open tank in the loft (that's what it would seem based on what you guys are saying). All sorts of shiite could get into the water
 
So do you think I should replace it with a combi or not?

How many people will live in the house, and how many bath/shower rooms?

if the answer is "1 and 1" a combi will be fine.

Otherwise, there is more to consider

The boiler is a good one, and pretty new, looks to me like it was recently fitted to replace an old boiler, possibly in preparation for the house sale.

You should (but might not) have in the loft a modern plastic cold-water tank with a close-fitting cover and an insulating jacket. If not, get one, and renew the pipe insulation too.

if you add an unvented cylinder, and have good incoming water flow, you could have unsurpassed hot water, better than a combi can give, and will not need a loft tank.

To my eye the cylinder looks like a 24x36" so it will contain round about a hundred litres of water, which is a good bath or maybe a couple of showers. It will take around half an hour to reheat from cold. Modern practice is to have larger cylinders. It depends if you want to go spending money straight away or live in the house for a bit. Winter is not the best time to tinker with your heating and HW.

Edit - no I see it is a 900x450mm, which is a bit small for a deep bath, so IMO needs changing anyway. I can see by the colour it is around 20 years old.
 
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By the looks of it and especially if it's grade 4 (thinnest copper grade that the older vented cylinders came in, don't do that grade any more I don't think) it's probably a standard vented indirect cylinder.

As suggested the size of cylinder is around the 100L mark. It will supply 1 bathroom (shower/bath) and kitchen at low pressure. The boiler, judging by the restorer label on it, is 9 odd years old. If it's been looked after then it should be OK but it isn't new, it should have a recent service cert if the house is being sold.

You need to decide what it is you would want from the hot water system and what your plans would be for the house. If you plan to add new bathrooms etc then that cylinder, if it is a normal vented cylinder, will struggle with anything more than 1.

A combi will really only serve 1 hot water outlet properly at one time (shower), it's just the nature of combi's. Any more and the hot water flow would be affected.

You would want to find out the cold pressure and flow into the property before deciding what system would suit.
 
so 5 people can have a shower one after the other without any down time in between)
How does that work in reality then? Is it 5 people in a que, towel in hand...Showering the second someone gets out? How about staggering them? Alternate days even?? Etc..
 
How does that work in reality then? Is it 5 people in a que, towel in hand...Showering the second someone gets out? How about staggering them? Alternate days even?? Etc..
Ive got 5 kids.. they tend to have a shower once a week on a Sunday. But we can manage around that.. just trying to understand the capability of the current system
 
You would get one bath/shower out of the cylinder that's there, if it's a standard vented cylinder. You would then need to wait for the water to heat up again - anything up to an hour with an old cylinder like that.

I do have to say though, one shower/bath per person per week, is that all???
 

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