Replacing with a Combi Boiler?

wayneski100

I've been looking around a house today (to possibly purchase). Most of the houses I have seen so far have had combi boilers, as does my current place. However, the one we looked around today didn't. 

Upstairs there was a hot water storage tank (in a cupboard in one of the bedrooms) and downstairs, in the kitchen, there is a Glow Worm Space Saver Mark 2 (I assume for heating). Bot of these look old(ish) - maybe more than 15 years old. 

Are these systems any good? Cost effective?
How easy is it to replace these with a new combi boiler? (I know I haven't provided lots of details so this might be tricky!)
What kind of a cost would I be looking at for the above change?

Thanks to anyone who reads this and offers some useful advice.

lesalanos

How big is the house? 
How many bathrooms? 
The system in place will work well enough but some people prefer combi boilers.  15 years old may mean the boiler & tank may need replacing.

Depending where you are it should cost 2-3K to replace with a combi, 2 to 4 days 

Rosa_Damascena

It wouldn't put me off buying and unless I had a family to look after and no immersion heater, I wouldn't bother replacing it until it goes kaput. 15 years means nothing! A good reason to change would be to liberate space; I would set aside £4k in total at that time, and that will cover any elderly radiators that might need an upgrade.

I happen to prefer tanks to combis, can't stand having to wait a few seconds for the water to get warm enough to use. They are up there with energy-saving lightbulbs for irritating. 

FreeBear

wayneski100 said: Are these systems any good? Cost effective?

System boilers with gravity fed hot water - Low hot water pressure unless you fit a booster pump or have a pressurised tank. Depending on your central heating schedule, you have constant hot water during the winter. In the summer months when the heating is off, you need to heat a full tank if you want hot water for washing. Depending on the distance between the tank and taps, you have to run the water for a minute or two before getting hot water out.

A combi boiler only heats water as/when you need it. It is at mains water pressure without needing booster pumps or pressurised tanks. You still get a delay in getting hot water when turning a tap on..

Given the choice. I would go for a combi, but I'm stuck with a system boiler & gravity fed HW tank. Up until recently, the boiler was running for an hour each day to keep the tank hot. The control has now been adjusted so that the water is only heated for bath night and water for dish washing is from a boiled kettle. An electric shower is sufficient for the rest of the week when a bath is not needed.

Bottom line - In the winter, not much to choose from between a system boiler & combi.

In the summer, a system boiler is grossly inefficient and a combi wins hands down for smaller households.

tacpot12

The Glowworm Boiler will be about 30 years old and may be in great condition or quite poor condition. We had to have one replaced last year as small leak had corroded the case to the point where it couldn't be taken apart for servicing, so had to be condemned. Replacement cost about £2500.

They are cost effective, but this is mainly due to how cheap gas is. 

RelievedSheff

We had an old Potterton system boiler with separate tank in our old house. It worked and it heated the house and hot water fine. The only annoyance we found was having to heat a whole tank of water in the summer when we really didn't need it as we had an electric shower so it was only for hand washing and washing pots. While the system was working we never really saw the need to replace it.

We now have a condensing combi boiler in our new house which suits us much better. We are only heating the water that we need when we need it. Despite being in a bigger detached house our gas bill is tiny in comparison to the old house.