Worth fixing or possible to fix old Marathon Myson

[spacecat]

just moved into new house and there is a Huge old Marathon Myson Boiler with a huge wall mounted timer that looks like something from the 1970's eastern bloc.


having said that it currently works quite well the radiators heat up v quickly and
and it is fairly quiet in operation

the downside is that the water from the hot taps is no where near as hot as the radiators.

Is it worth fixing this/ Can it be fixed? would the parts be available.


I am planning to upgrade the system at some point possibly direct replacement or a combi (its currently a gravity system cold tank and boiler)

Also the cold water pressure in the bathroom is very slow but the kitchen tap seems very good pressure.. why would this be the case?

thanks

 

[iep]

The cold water in the bathroom will be from the cold water tank in the loft. Being garvity fed it will be relatively low pressure especially if the tank is not far above the bathroom.

The cold water in the kitchen has to be taken direct from the water main as drinking water cannot be taken from a cold tank (due to bacteria etc). So kitchen cold tap wil be much higher pressure.

The hot water from the taps should be about 60-65 degrees and is controlled by a thermostat on the cylinder (in conjunction with a zone valve that controls the flow of hot water from the boiler that then passes through the heat exchanger in the hot water cylinder). If the water is not hot enough, locate the thermostat on the cylinder and try turning it up. If no change, you might need a new cylinder thermostat (about £10 and easy to fit yourself if you can wire a plug).

If that does not fix it then the zone valve may be at fault. Without knowing more about your system I can't really advise on this.

Having said all that, if the boiler can heat the radiators then it can also heat the water in your cyclinder. The fault (if there is one) is not with the boiler itself and should be relatively cheap to fix.

Hope that helps.

iep

 

[kevplumb]

I am planning to upgrade the system at some point possibly direct replacement or a combi (its currently a gravity system cold tank and boiler)

what zone valve ??

dont fit a combi they are not the universal answer to all probs

 

[iep]

'what zone valve ?? '

I'm guessing that it is an s-plan or y-plan system and so will have two 2port or on 3port zone valve to control when the heating and HW loops are active. Perhaps I'm using the wrong name but was pretty sure they are called zone valves.

On my own system, the 2 port zone valve to the HW cylinder jammed partially open (but not fully). This meant that the cylinder took ages to heat up and water could be a little 'luke warm'. It also meant that the cyclinder was always being heated when the heating was on but that is another story.

Cheers,

iep

 

[kevplumb]

yer your guessing and not very well fella

 

[45yearsagasman]

Too much guessing on this site.A gravity system would only have a zone valve fitted if was c plan.Without enough info on system design its hard to give accurate answers.

 

[iep]

Not sure why you guys are so sure I am off the mark here but happy to be told why I am wrong.

For the record though I have a gravity fed s-plan (not c-plan) system using two Honeywell V4043H 2-port zone valves. I've owned three properties using this configuration. Based on that, I reckoned it was very common.

Either way, IMHO, the cylinder thermostat is worth a look.

Cheers,

iep

 

[kevplumb]

quite simple really

what you have or have had or have seen

dont mean jack

let the OP tell you what they have then dive in

check the no of posts !

been down this road too many times

 

[spacecat]

The cylinder does not have a thermostat that I can see it does have a plug to use electricity to heat. There is a honeywell thermostat in the hall

 

[kirkgas]

Not sure why you guys are so sure I am off the mark here but happy to be told why I am wrong.

For the record though I have a gravity fed s-plan (not c-plan) system using two Honeywell V4043H 2-port zone valves. I've owned three properties using this configuration. Based on that, I reckoned it was very common.

where do you have the 2 x 2 port valves on a gravity system? on a gravity hot water system there should be no valve or restriction on the gravity primary circuit and 1 x zone valve on the heating circuit

 

[spacecat]

i used the switch on the immersion to heat up electrically and after 30mins the hot water from the taps is now piping hot.

does this mean the problem is with the boiler?

 

[kirkgas]

i used the switch on the immersion to heat up electrically and after 30mins the hot water from the taps is now piping hot.

does this mean the problem is with the boiler?

not really, it could be air or blockage in the pipes at the cylinder amongst other things

 

[Boilerman2]

Er- 2 port Valve in Gravity loop = C PLAN, 2 port valves on fully pumped system =S PLAN so im with 45yrs on this one!

 

[spacecat]

i used the switch on the immersion to heat up electrically and after 30mins the hot water from the taps is now piping hot.

does this mean the problem is with the boiler?

not really, it could be air or blockage in the pipes at the cylinder amongrst other things

How would you sort out an air or blockage issue?

 

[iep]

Spacecat, to give you more detailed info it would be very useful to know what type of sytem you have. The link below shows three common types of system for CH and HW plumbing:

http://wiki.diyfaq.org.uk/index.php?title=Central_Heating_Controls_and_Zoning

My own system is an s-plan. In my system, the zone valve that fed the cylinder had failed and was limiting flow through the cylinder. This resulted in slow heating of the water. If your cylinder is badly insulated it might also limit the max temperature achievable.

Have a look at the valves on your own system. I don't know where they are likely to be located in your house but it is common to find them near the boiler or near the HW cylinder.

If/when you find the valve that provides the hot water flow to your cylinder put your hand on the input and output sides of the valve. If they are at a noticably different temperature then the valve may be at fault.

I'm not saying that this is definitely the fault but I'm trying to provide simple tests you can do to check out the cheaper parts of your system before you decide to replace larger and more expensive items.

Since your boiler can heat the water for the radiators, it is also going to be possible for it to heat the water in your hot water cylinder. So, the fault is likely to lie in either the valves or the pipework leading to the cylinder.

You mentioned that there is no thermostat on your cylinder. This may be true but is unusual (in my experience). My own thermostst was loaceted behind the cylinder and was quite out of view. It is usuallly attached with a metal or rubberised band around the cylinder which makes it easier to locate.

Have a look at your system and see what you cna figure out.

Cheers,

iep