Hi to all, I’m looking at replacing open vented Boiler and thermal storage system with high out put for Combi ! !

[Miller4]

Hi,

I hope it’s ok to post in this section ?

looking to replace my vaillant ecotec boiler and Gledhill Boilermate ll should I replace it like for like if so any recommendation's !! or should i switch up to a Combi high output 36 / 40 Intergas I was thinking.

Your knowledge and experience would be highly valued on this Subject. Also do these new breed of combis actually produce the hot water flow they claim to offer ?

hoping someone out there can advise on this subject.

 

[Madrab]

All comes down to what you want and have in the property as far as showers/baths etc and how the cold mains is. That would be the starting point.

As far as the system you had then you would have had hot water I would presume you had all the hot water you wanted, you won't get that with a combi. Max 1 fully flowing hot tap at a time with a combi.

 

[muggles]

The Intergas 36/40 is 36kw (nominally - actually only 32.7kW) to hot water and 40kW to heating. It's no more powerful on hot water production than the 36/30.

Much as I like Intergas boilers, I think you might be better off with a Navien NCB700 54Kw. https://navien.co.uk/product/ncb-700-gas-condensing-combi-boiler/

 

[DP]

Good thing about IG is that it can be used as open vented.
Muggles, I am not familiar with Navien, can it be used same way? Ie option to install a combi as OV

 

[muggles]

Good thing about IG is that it can be used as open vented.
Muggles, I am not familiar with Navien, can it be used same way? Ie option to install a combi as OV

Hmm, ish. It doesn't specify sealed system in the manual although it does suggest filling to between 1.0 & 1.5 bar. The minimum system pressure before triggering a fault code can be wound all the way down to 0.2 bar in the installer settings though, and I do have an oil fired one successfully running open vent (they share the same controller). I'd therefore say that yes, it would work OV provided there's more than about 3m between the F&E and the boiler, but it's not quite in the spirit of the installation manual...

 

[Miller4]

Hi,

thanks for replies.

is it cheaper to run a Combi or thermal store if i upgrade to a newer modern store ?
Reason I mentioned IG a Plumber recommended it to me had problems with current vaillant heat exchanger blocked had system power flushed and then it blocked the second heat exchanger. I have 10 mm micro bore to rads been told to use magna-cleanse on system I have a magna clean filter fitted now, system is blocked now my rads are Luke warm B G look after it on contract engineer told me need a new thermostat yet it turns heating on and off but luke warm top of rads

 

[Miller4]

Answer to one of your questions my current gas boiler is in my garage Boilermate ll is upstairs in airing cupboard so yes there more than 3 metres in length away from each other.

 

[Madrab]

Again - what do you want as far as the hot and cold water systems in your house is concerned. If you want to use multiple hot water outlets at the same time then a combi is usually a non starter.

 

[muggles]

Sounds like the powerflush wasn't done correctly if you're still getting blockages. Thermal stores run too hot for modern boilers to be efficient so a combi would be cheaper, but you need to get that system properly cleaned out before you contemplate fitting a new boiler to it. Ideally the Boilermate should be drained, isolated, and bypassed to do this as they tend to be full of sludge and are very difficult to flush. There's a reason thermal stores are often known as sludge buckets

 

[DP]

Hi,

thanks for replies.

is it cheaper to run a Combi or thermal store if i upgrade to a newer modern store ?
Reason I mentioned IG a Plumber recommended it to me had problems with current vaillant heat exchanger blocked had system power flushed and then it blocked the second heat exchanger. I have 10 mm micro bore to rads been told to use magna-cleanse on system I have a magna clean filter fitted now, system is blocked now my rads are Luke warm B G look after it on contract engineer told me need a new thermostat yet it turns heating on and off but luke warm top of rads

I use to fit IG but not anymore as the heat exchanger needs opened up every two years to replace mother of all O ring seal.

WRT your boiler, what is the temperature of the flow pipe at the boiler then at the radiators, same for the return pipes.

You need someone who can think the problem through rather than someone making wild guesses.

I would instal a megnaclean (Adey). This filter is by far the best one for catching muck

With the Boilermate, check the boiler connections to it. Are these hot? The cylinder controls the boiler. As Muggles says, there will be plenty debris in the Boilermate. I would be tempted to fit a larger Adey filter to intercept the muck moving from the cylinder to the boiler and clean filter every week and take it from there. These mag filters are good- this is from personal experience

 

[Miller4]

I have Adey Magnaclean fitted the muck you can see on it !! I hadn’t cleaned that filter out for sometime as we have B G contract thought that they do that when servicing boiler ? there is now hardly any thing on magnet a week or so later but going to have 2 XP 28 mm fitted the bigger version once I have system sorted and prior to a refit.

i wasnt at home when chap did original power flush is it worth having a Magnacleanse done on system i have drained heating down couple of times put cleaner in system myself couple of years back. Been told to put couple bottles X 800 in for a week then flush it out. the water in boiler is that separate from heating water i can see a brass drain off at bottom of cylinder should I drain and flush that a couple times ? Boiler mate ll connections are fairly hot but like rads when heating is on they become Luke warm Same on gas boiler flow is hot but not to point that I have to remove my hand from it return is even cooler.

 

[Miller4]

I’m hoping anyone who may be reading this can give me update on what i could have installed next ? ? ? I’m not a big Combi fan but saying that it was over 20 Yrs ago time you had run a bath water was cold in winter months, I do like stored hot water on demand.

But saying that Muggles mentioned a Navien Combi I looked them up do we know how reliable they are ? and there heat Ex are they less likely to block up and do they actually produce the LTRS of HOT water that they say ! !

 

[Miller4]

I hadn’t mentioned I have a total of 19 Rads that includes a large double in my garage, so I would say 9 of which are doubles if I include bathroom towel rad. 2 of which have been pipped off one rad from our dinning room and go in to conservatory they never get very hot but will be getting sorted With new boiler.

 

[MNW67]

You really need to read Madrab's posts and decide what you want from the system in terms of using multiple hot outlets at the same time. Nobody can begin to answer without that information. Also how good is your cold mains pressure and flow? Boiler output is not the only consideration with combis.

The other alternative would be an unvented mains pressure hot water cylinder. You would still get a high flow of mains pressure hot water like your Boilermate but in a different way.

 

[Miller4]

Ha right,

no I don’t really need multiple hot outlets at the same time. Just enough hot water to service one bath or shower at any time, however I would just like to future proof the house we have 1 bathroom and 1 ensuite with 4 bedrooms. But as I stated I quite like the idea of having stored hot water on tap, I’m just thinking long term running costs going forward am I overpaying with a thermal store ? Would unvented system be any more cost effective to run ?

Thanks again