magnaclean filter and low loss header

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Should I consider getting a magnaclean filter installed on my fragile dual Keston Celsius 25 system? If so, where? As it is primarily to protect the boilers, my initial thought is it should be in the low-loss header between the primary return and the boilers, maybe on the far right of the picture, next to the gas meter, so it is immediately before the boiler returns.
 
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I would say yes, to near the gas meter.
 
Yes ....

That would be fine

Also consider fitting the dual magnaclean that has a stariner built into it as well
 
Do not fit the Magnaclean or the Fernox as they have plastic bodies. The pipe lugs on Magnacleans regularly rip off when the lid is taken off. It happened with me. Luckily the filter had two proper full-bore isolating valves, rather than the Mickey Mouse valves they supply.

Fit a brass Magnabooster. A bit more expensive, but the best. It will be insurance for the two boiler setup. Initially clean the filter every week, then every month then once a year. You will be amazed at how much magnentite they pick up. The Magnabooster is very easy to flush out.
 
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Excellent advice from GT.

The Magnacleans could rival the Kestons for reliability.

My question would be, why bother fitting a filter to a Keston? It is guilding a turd, surely? Why not wait till they go in the skip and fit one then?
 
Excellent advice from GT.

The Magnacleans could rival the Kestons for reliability.

My question would be, why bother fitting a filter to a Keston? It is guilding a turd, surely? Why not wait till they go in the skip and fit one then?

Over 10 years ago Kestons were excellent quality. The condensing boiler they made with no electronic board and a a spiral heat exchanger with a top mounted burner (I think they were the first to do this) was superb and worked brilliantly on thermal stores. The boiler was simple and effective. It cycled like hell on direct systems, of which Keston said did not harm the boiler, but sung on a thermal store with two anti-cycle thermostats. I know of a few that are approx 15 years old and have never gone wrong at all. They are simple to fix with not much in them.

They then started to make complicated boilers to compete with Vaillant et al, and sell to the mass market. Their reputation suffered greatly. The quality went down with take-overs.

I believe the quality is picking up.
 
I would fit the Debris cleaner in the Return pipe to the left of the Expansion vessel in your pic, this way it would protect both boilers without compromising the low loss header! ;)
 
Is it your boiler?
Sadly, they are. I tried in an earlier post to get them condensing AND heating DHW but I've given up; I couldn't get the boiler return to stay much below 60°C without taking the flow in the LLH too low. At least I don't have frozen condensate problems. :confused:

The Kestons only have a single flow and return each. I guess that makes them 'heat only' boilers. Do 'system' boilers generally support 4-pipe installations with separate DHW and CH temperatures?
 
I would fit the Debris cleaner in the Return pipe to the left of the Expansion vessel in your pic, this way it would protect both boilers without compromising the low loss header! ;)
I understand that the flow in the LLH is needed to protect the heat exchangers from cracking again (2 so far). I've already opened the gate valve wide to maximise LLH flow. So, are you recommending putting the filter in the primary circuit return to keep the LLH unrestricted?

In car engines, they used to have by-pass oil filters that were much finer than full-flow filters. These kept the oil cleaner before modern detergents as they could use the full pressure of the pump, but didn't offer 100% protection from larger particles. Are all central heating filters designed only for full flow or are some put into a by-pass?
 
Is it your boiler?
Sadly, they are. I tried in an earlier post to get them condensing AND heating DHW but I've given up; I couldn't get the boiler return to stay much below 60°C without taking the flow in the LLH too low. At least I don't have frozen condensate problems. :confused:

The Kestons only have a single flow and return each. I guess that makes them 'heat only' boilers. Do 'system' boilers generally support 4-pipe installations with separate DHW and CH temperatures?

The coil in the cylinder could be too small. Condensing Performance could be improved by using a plate heat exchanger, that takes both boiler's outputs and some more. That way the return temperature would be low from the cylinder with the DHW cylinder reheating very quick, meaning you could downsize the cylinder saving money.

You could have a blending valve in the return from the cylinder set to say, 50-55C. This way the return will be under the dew point most of the time heat DHW.

Did you write you had 2 cracked heat exchangers on the Kestons? Then I would use a blending valve on the return to the boilers, this ensures the temperature is not too low on a cold start and keeps the condensing efficiency high.

How are you sequencing the boilers?
 
not sure your crude version of a low loss header is of much use. I think you would have much more luck with lower return temps with purpose made version.

I'm sure more experienced commercial guys on here would have some thoughts
 
It will need to go in the common return to the left of the expansion vessel.

Sorry boilerman didn't read your post till after I posted. ;)
 
not sure your crude version of a low loss header is of much use. I think you would have much more luck with lower return temps with purpose made version.

I'm sure more experienced commercial guys on here would have some thoughts

It isn't a header snb.

A simple straight forward reverse return set up ;)
 
The coil in the cylinder could be too small.
The 300l cylinder can take the full output of both boilers, at least when cool. However, I need to keep the boiler flow above 65°C to heat the DHW above 60°C and trigger the cylinder thermostat. I have tried partially closing the LLH gate valve to increase the temperature rise across the boiler to 20°C at full load. Unfortunately, at part load, the temperature rise drops away to about 6°C at 'cruising' load. I'm nervous about pushing up the temperature rise across the boilers as I've already had 2 heat exchangers replaced. I notice that the first boiler to come off full load drops its pump speed. I'm worried that having any restriction in the LLH will allow flow to reverse (or at least slow way down) if one boiler's pump is pushing harder than the other.

I'd wondered about a temperature limiting mixer instead of the gate valve to keep the boiler return at 45°C and set the feed to 65°C. I decided against that as it is easy to increase the feed above 65°C. I'd also want to replace the knobs with pre-sets. This would limit heating in cold weather... Is there a mixer that allows a fixed temperature rise in a LLH?

You could have a blending valve in the return from the cylinder set to say, 50-55C. This way the return will be under the dew point most of the time heat DHW.
I don't see how that would affect the temperature in the LLH.

How are you sequencing the boilers?
I currently run the CH 24x7 with a programmable room thermostat. The DHW I have on for an hour in the early morning before the CH and again in the afternoon. The secondary DHW circulation (bronze pump) wastes a lot of heat.
 

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