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Central Heating

Add pump to gravity hot water system or change to unvented cylinder?

Anonymous user 15/03/2024 - 2.34 PM

Hi, I currently have a gravity hot water system - have a 110x60x60 water tank in the loft, the water pressure in the bathrooms (3 on first floor) are very low, especially the master bedroom en-suite (the furthest from the tank) which is unusable for shower. Did a little research and seems that I have two options: 1. Keep the existing system with the loft cold water tank. Add one pump to feed all bathrooms or add multiple small pumps for each bathroom. This system is the safest system as the tank and cylinder is not pressurized, but the water quality could be getting worse along the time when the limescale built up and dust etc get into the tank (current tank does not have a lid and the plastic cover is broken so water is really not clean - will need to replace the tank if keep the current setup). Question is do I add a large pump to supply all bathrooms (will this effect the toilet cistern?) or multiple pumps for each bathrooms? is pump noise a concern? 2. change the cylinder to unvented cylinder and move to loft, cold water will be mains supply pressure. With 22L/min flow rate tested at ground level tap, am I guaranteed to have good shower performance in all bathrooms ( assuming only one in use or 2 showers simultaneously). My only concern would be the safety of the cylinder as it may blow up if not fitted right. Considering I will be living in this house for a long time so the cost does not play much here, only looking to the best option for the long run. Thanks a lot for any advice in advance.

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3 Answers

Clark + Withers

Rating: 5 out of 5

Epsom

Hi Supra, From your two options I would go with the Unvented cylinder as you have amazing water pressure this would give you the ability to run all showers at the same pressure but would involve running a new mains pipe up to the unvented cylinder location and then a hot pipe in 22mm to make sure that all taps are supplied with decent pressure. If you go for the first option then you would need a new cold water storage tank which would hold more water and then add the shower pumps ideally I would add separate ones for each due to them having a tendency to burn out when put under a lot of pressure. With this you would also get the noise of the pump which a lot of people do not like. The unvented cylinder is the most popular choice for homeowners who want amazing pressure and have multiple bathrooms. As long as you get an unvented cylinder qualified engineer you will be fine its when you get someone not qualified that issues arise. I hope that helps

Answered27 March 2017

QUALITY HEATING SERVICES

Rating: 5 out of 5

Exeter

An unvented cylinder installed by a competent engineer will give you the best hot water. Although 22L/min is not very good flow if measured at the first cold tap of the main cold inlet, you also need at least 2 bar pressure at ground level (std house). Installing an unvented cylinder in the loft will require a very strong sturdy base a 210lt tank weighs quarter of a ton when full!

Answered30 March 2017

D & R Property and Plumbing Maintenance

Rating: 4.9 out of 5

New Romney

before you go for unvented check your water supply for l/min and pressure,but do this at times of local high usage ie 6am to 8am/or 5pm to 8pm as if you check any other time you are checking when few people are using water so your true peak time flow and pressure reading will be wrong.

Answered3 May 2017